It depends. Sometimes it ends suddenly, like it did with my third ATF, who exhibited obvious personality problems which basically ended our relationship then and there. Sometimes, it just builds up gradually, like with one of my recent favorites. She was nice at the beginning, but the last time I got dances from her, we ended up getting the VIP room instead of the regular lap dance room and she spent most of the time sitting around talking, essentially using the room as an excuse to not stage dance. I told her if she wasn't going to dance, that was it. I mean, I enjoy talking with her, but there's a limit to talking. I'm also glad you can call that club up and have them tell you who's dancing, so that if she's there, I can avoid her.
In the end, mostly, you just know it's over.