I agree with Serp. I'd want to address why I'm suspicious in the first place with my partner, and try to handle it with open communication. If I can't do that, then there's definitely something wrong, and it's something that I feel is far worse than my partner's boots winding up under someone else's bed.
I agree with Succubus as well, especially if it were, say, things I possibly said while upset or angry. It's been something I've been working on, but in the past, I've said some pretty darn flippant, if not outright disrespectful and mean, things about my partners because I was angry with them for something while I was talking with my friends. Did I feel that way after the disagreement was resolved? No, because it was resolved. However, until then, if the pot is simmering, it has a tendency to spit, should the lid not be settled properly.