there are discrepancies in your relationship. he gain weight and after living together you know he's a slob. but you don't mind those. for some ppl that's a negative changes.

i assume he doesn't like you're gaining weight but he never said anything because he gains weight too. and it's maybe true that he's becoming less attracted to you.

maybe have a sit down and try to get better together. you try to lose weight and you asked him not to be a slob and start helping out or he tries to lose weight as well. don't ask him to do both cos he will feel it's unfair. i think it's better to be someone that he wanted rather than policing his social media usage.

with the insta girls. personally i think it's hard to supervise that. those kind of stuff also appears in my feed and occasionally i look at them. im married and i know my wife dont have body like those models but im still masturbating to video of us having sex the most.