It depends on what you mean by got fat tbh.
If he put weight on, a couple of stone, it wouldn’t bother me at all. He has put on around a stone since we met and I genuinely prefer his body now. I’m not into the super shredded really slim muscular look on guys. I genuinely find his softer rounder tummy way more attractive! Though to be fair he still has a body that would turn heads if he went shirtless, but I obviously have seen the slight difference.
I gained two stone since we met (I was the slimmest I’ve ever been when we met due to stress), realised and have shed 75% of it. Half a stone to go. He claims he fancied me just as much a pound away from being clinically overweight, whether or not that’s true i don’t know, but he’s always said he doesn’t find someone’s body a big deal as it’s about personality and face for him. I wanted to lose weight for me and I’m so glad I have and am.
But if either of us gained enough weight we were clinically overweight, certainly obese, I don’t think it’d be unreasonable to walk away. I really hope and think neither of us would ever let it get to that point. I feel like even if he gained five stone I’d still fancy and love him but you just can’t know until it happens. I think i would do what I could to support and encourage him in losing the weight if he wanted to. But I’d be concerned about the messages he was sending our kids, the lessons they were learning about taking care of their bodies and health, I’d be worried about his future. I don’t want him to develop weight related diseases and have his life cut short.
I believe I’d do everything I could to support him and help, and I can’t imagine ever wanting to walk away, but I also know being attracted to/proud to be seen with your partner is a major part of many relationships and I couldn’t possibly judge anyone for realising that their partner had changed so much from how they were when they first met, they weren’t happy with them anymore. Especially as weight is something within your control. You could equally argue you owe it to your partner to be at least relatively fit and healthy for your futures and if you choose to let it go, you have to accept the consequences on your relationship I guess.
Ultimately anyone can leave anyone for any reason they wish, all that matters is that they feel it’s a good enough reason for them. Relationships aren’t prisons. If someone is repulsed by their partner for something they could choose to change, and they can’t bear to be in the relationship anymore, that’s their choice.