So one of my player's characters is a bit evil...(and I need help learning to say no)

[Togath]

So.. Yea. Odd sessions with a player recently.
All started when they explained they wanted to have their character get pregnant, with another PC as the father... By using magic to force them into.. well, you get the idea.
After pointing out that a: even if he's a guy, it's still rape, and b: he's immune to the magic she was going to use, she decided to just try to romance the character.
So problem solved there(sorta. I still worry something like this may be a bit too weird for the other players, since it's been a fairly normal game, and suddenly dragon/catfolk breeding has come up)
And another came up.

The player decided they wanted to use that same forced love magic to try to seduce merchants for items, and make a permanent version in order to control the daughter of an npc the party met, have her run off with the player,, who had planned to change her appearance using magic(different hair colour and style, disguising her eye colour, a new wardrobe, those kinds of thing) and give her a custom item to change her between human, catfolk, and cat forms.

And for some reason, I had trouble saying no...
So they did seduce a merchant, though we admittedly didn't rp all of the "encounter" I still felt a little weird when I realized that it was still a fairly nsfw encounter, even if we didn't rp what she did with him in the back room of the shop.
After getting some enchanted items as "payment" from him she then decided to try the "control the npc's daughter with love magic" plan. And I still didn't manage to say no for some reason.

She convinced the npc's daughter to share some wine with her(laced heavily with the permanent love potion). Once the npc's daughter was enthralled the player convinced her to go by a different name, leave a note for her family saying she had run off to join a band of adventurers, start calling the player's character "master", get her hair lengthened(by several feet) and dyed using magic, and finally put on the magic item that let her shape shift, and take one the form of a cat whenever she was around the rest of the party, or her family.
I don't know why I didn't say no during any of this. Just couldn't manage it.

So now the player has an enslaved(player's choice of words) npc that they've forced to love them.

Any advice for what to do now? Should I just let the issue go and just try to say no next time something like this comes up? And any advice for getting better at saying no when a player wants to take actions the other players(or characters) wouldn't like?

[Cazero]

Looks like that girl should have had a HUGE circumstance bonus on the saving roll against the love potion to me, and a new roll for each new demand. If she's enthralled regardless, I think that in this situation, her parents should guess what happened. Like, exactly who she left with. Now, the merchant might be too ashamed of that discount offer to ever act on it, but otherwise a bounty is on order.

Consequences to the players actions has DM fiat written all over it. As long as law enforcement is not made by some kind of god moded do-gooder, there is nothing wrong about making your players wanted criminals for a crime they did commit.

[Ettina]

Take the player aside between sessions and say that you're uncomfortable with how dark this story is getting, and ask them if they'd be willing to either change this character's behaviour or have the character leave the story and make a new character. (Could die, or just decide to go somewhere else and do non-plot-important stuff like raise her baby.)

[Sidmen]

Honestly, I'd let the player know that her character has slipped into DM control, and adviser him/her that rape characters are not appropriate for your table.

[LokiRagnarok]

If the DM took over my character without prior warning or even a hint that what I was doing was unwelcome, I'd be massively pissed off.

[Sidmen]

If the DM took over my character without prior warning or even a hint that what I was doing was unwelcome, I'd be massively pissed off.

Perhaps you should avoid raping people, then?

Maybe that's the tiniest bit unfair. Maybe the OP didn't have the (IMO) mandatory session 1 discussion about what kind of characters are going to be appropriate for this campaign. If it wasn't laid out at the beginning that the group should be heroes (or mercenaries, or villains, or whatever), then yeah - I can see giving a warning before more extreme actions.

In that case, I'd shoot an email to the offending player telling them that their character's actions were wildly inappropriate, and that they can either opt to play a different character - or we can retcon the offending gameplay and never speak of it again.

[Azurefenrir]

Echoing what everyone else said in this thread.

The issue here is that you are uncomfortable with one of your PC's evil actions. In this case, the best way to solve this is to pull the player aside at some point (maybe through e-mail or phone) and discuss the issue with him/her. Don't criticize his/her roleplaying or imply he/she is at fault, but just announce that you are not comfortable with this sort of thing in an RP and asking him/her to respect it and play a different kind of character. Assuming that he/she is a mature player, he/she should be receptive to your concerns, and dialogue will naturally flow until a compromise is reached (or you are at each other's throats, but you can make this not happen).

It's also better than juat saying "no" in general, because players tend to react to a blatant "no" in the same way they'd react to a parent scolding them - often with defiance, because they'd see your actions as just "railroading" without understanding why you are doing so.

EDIT: If you aren't personally bothered by it, but are afraid it might be too weird for the game, talk it over with your other players as well and see if any of them are actually uncomfortable. Usually, players get mad if another player takes away their agency, though how players react to NPCs being treated this way vastly differs depending on personal views and such. There is no badwrongfun in roleplaying games, but making other players uncomfortable is a problem - though a problem you need to work out OOC with everyone present.

[LokiRagnarok]

Perhaps you should avoid raping people, then?

Maybe that's the tiniest bit unfair. Maybe the OP didn't have the (IMO) mandatory session 1 discussion about what kind of characters are going to be appropriate for this campaign. If it wasn't laid out at the beginning that the group should be heroes (or mercenaries, or villains, or whatever), then yeah - I can see giving a warning before more extreme actions.

We are in agreement here - if that discussion was had, I would obviously consider it a warning in the sense I wanted.

However, I have a suspicion such a discussion had not taken place here.

[Mr.Moron]

Gross. Why even keep playing with them?

[veti]

It never ceases to amaze me, how PCs can murder, maim and burn as many people as they like, but introduce sex into the game and suddenly it's "Ewww, gross". (Yeah, I know, there's a difference between sex and rape. But the OP makes it clear they're not comfortable even with consensual NSFW RP.)

Is Evil a playable alignment in your game? If not, then you should probably have made that clear up front, and if you didn't, I suggest doing it now (for everyone), with a particular aside to the player that his/her character is very close to NPC-dom unless they change their course.

[Togath]

My issue is that while I didn't mind the session(no actual sex occurred, just some moderately kinky things), I had worried the others might kick the player if they found out(I don't might sex or kinky stuff in games, but as I said, I had been worried the others might).
I've talked, and it sounds like OOC the players are fine-ish about things(probably, haven't talked to them all yet).
Also that apparently by RAW the enslaved girl should get will saves, so she might be able to break free.

Alignment-wise.. I don't enforce alignments, other than for mechanical effects(smites/ detect x spells), so chaotic evil would be perfectly playable, especially since I removed the code of conduct from any classes with one(so the party paladin isn't at risk of falling from associating with the evil character).

And as a plus, the player really has made efforts to romance the dragon character, rather than molesting him ^_^.

[Red Fel]

I have personal views on what's going on here, but I'll keep them to myself unless solicited. It sounds like you're simply asking what to do about your issue. That said...

My issue is that while I didn't mind the session(no actual sex occurred, just some moderately kinky things), I had worried the others might kick the player if they found out(I don't might sex or kinky stuff in games, but as I said, I had been worried the others might).
I've talked, and it sounds like OOC the players are fine-ish about things(probably, haven't talked to them all yet).
Also that apparently by RAW the enslaved girl should get will saves, so she might be able to break free.

Alignment-wise.. I don't enforce alignments, other than for mechanical effects(smites/ detect x spells), so chaotic evil would be perfectly playable, especially since I removed the code of conduct from any classes with one(so the party paladin isn't at risk of falling from associating with the evil character).

And as a plus, the player really has made efforts to romance the dragon character, rather than molesting him ^_^.

So... You don't mind what this player did. The other players don't mind what this player did. The PC's alignment may change, but it will not impact gameplay in any meaningful fashion. And the PC is now trying to "romance," rather than use force.

In short, nobody is bothered, nobody is impacted in any meaningful way.

... Where is the issue again?

Now, if you actually do have an issue (and the personal view that I mentioned above, which I have decided not to keep to myself, is that you do) the course of action prescribed by others is pretty solid. Have a sit-down, explain that you may not be penalizing people for alignment, but you don't want to have to deal with the adventures of the Randy Rapist at your table, and it needs to stop. Give fair warning and give the player a chance to be heard. If you're concerned that the other players would want to boot him (and yet, paradoxically, you mention that they're fine with it) then maybe you should just come out and say that it bothers you. Because that's what it sounds like; it sounds like you're bothered. You have a right to be, and if you are, just come right out and say so. One thing that really gets my goiters is when somebody is bothered by something and attributes it to someone else. ("Bob said you smell bad. Of course, I have no problem, but let's not upset Bob, so here's some soap...")

You are the GM. Be authoritative. If something bothers you, say so.

As a general rule, when the other players say no, they say no. No, as they say, means no. Giving a player the power to override player agency is as bad - and at times, worse - as overriding player agency yourself. I'm not saying to tell the player what their character can or cannot do; if they're technically capable, they are. But unwanted actions between PCs is PvP, very simply. And once a player has initiated PvP in this manner, they are free game. They lose the right to complain if the other PCs kill their PC, or ditch him, or hand him over to guards or Dragons or Inevitables.

That's how you say "no" to a player like this. If he's doing something that bothers you, tell him so, and tell him that it stops. If he's engaging in unwanted PvP conduct, advise him that his PC will spend the rest of the campaign with a no-consequences target on his back for the other PCs to enjoy.

Every player has a choice. Sometimes, it's a fairly obvious choice, but it's always a choice.

[Curbstomp]

Ja. What Red Fel said.

[Flame of Anor]

So... You don't mind what this player did. The other players don't mind what this player did. The PC's alignment may change, but it will not impact gameplay in any meaningful fashion. And the PC is now trying to "romance," rather than use force.

In short, nobody is bothered, nobody is impacted in any meaningful way.

... Where is the issue again?

Are you forgetting the mind-controlled sex slave? Seems like an issue to me.

[Sartharina]

Are you forgetting the mind-controlled sex slave? Seems like an issue to me.

That's the only issue I'm seeing a problem with.

[Togath]

That's the only issue I'm seeing a problem with.

Honestly, after some more thinking, I realized that was the only part that bothered me at all.
I might allow her(the mind controlled slave) will saves to try to break free(since I didn't realize the spell allowed more than one), but I'm not going to actively punish the player.

[Flame of Anor]

That's the only issue I'm seeing a problem with.

But it's a pretty big issue nonetheless.

[Red Fel]

But it's a pretty big issue nonetheless.

Scroll down. I agreed with you.