Or relationship foreplay.
Potential TMI tiemz!
If you say to me, "you wanna have sex?", I'll start overthinking it: I'm pretty tired, I've got work tomorrow, do I really feel like it? and so on. But if, instead, you start smooching and snuggling and... uh... etc., chances are pretty soon I'll be into it.
Same sorta thing with relationships as a whole.

IMPORTANT DISCLAIMER: This absolutely does not apply to everyone. It's purely personal preference/opinion, an inside perspective on how it works. This is explanation, not advice.