If I don't say anything upfront, most guys will seem cool with it at first. But then later reveal that they're not. I was just talking to a guy tonight. We met online maybe 6 months ago. I haven't been back to where he lives yet, so we haven't met up, but he was probably my best prospect. And we'd sexted in the meantime.
Tonight things are getting steamy and he tells me how much he wants to fuck my pussy.

I was like, "well.. that's literally the one things that's off limits for me." We've talked about a lot of light DBSM stuff, bringing in another person, etc. Nothing else have I said no to.
He goes on to tell me how hard it's going to be for him to not fuck my pussy. He can't help himself in the moment. Sorry, but I'm 100% not having sex with you now. If you cannot respect my ONE LIMIT, how am I going to let you handcuff me?
I wish one day I could find a guy who is actually INTO it. I'm not sure he exists though...
/rant