You have to lay the law down early. I always tell my dates, "If you ever get fat we're done. No "Just gimme a chance" No "I'll work on it" No "But I like it this way" I stay trim and attractive for myself and because I want to look my best as a courtesy to my partner and I expect my partner to have the same respect for me." It always starts slowly, more time with sedentary hobbies, less time at the gym or on active hobbies, and I always get called the bitch for point it out "But babe I've been spending more time with YOU." Like no, you've been spending more time with food. I think I posted on here once about breaking up with a guy that gained substantial amount of weight (like 20lbs) in just a few months of the relationship and after I broke up he made sure to go to the gym when he knew i'd be there. Nope, not taking your lazy pathetic ass back.