Why would my boyfriend dumped me for gaining 70 pounds?

I was very thin and used to model. I was 118lbs when I met my boyfriend and we’ve been together for two years. I started putting on weight and he likes me with more weight on me but when ballooned up to 70lbs. He started being resentful, doesn’t want to touch me and we haven’t had sex for a couple weeks. He said I needed to watch my weight and if I don’t care enough to care about my weight or be lazy and fat, he’ll break up with me. I’ve been trying but it’s so hard and I don’t like exercise! Plus skinny, thin and slim are SO overrated! How about thick or big girls?

I went from 118lbs to 188lbs. And I’m 5’5. My boyfriend is still fit and 5’11.
He dumped me yesterday and I ended up moving back with my parents after that hard, terrible break up.
I thought size didn’t matter. Plus I was tired of being skinny! I have been wanting to put on weight for years but I didn’t think I would go this far.

Updates
9 mo
He found me or hotter when I was like 125-130lbs.
Why would my boyfriend dumped me for gaining 70 pounds?
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