Hi everyone, I have been lurking here for a while, but things have come to a head for me and frankly I'm not sure how to handle this situation with my boyfriend.
I work very hard to maintain my weight. I am fairly comfortable at around 110 lbs, and historically have kept it there ± 5 lbs with portion control and a primarily vegetarian diet (I eat whatever I want when I go out, but cook vegan/vegetarian exclusively). However, since I started dating my boyfriend last May, my weight has gone up to anywhere between 115 and 120. These may not seem like high numbers, or much of a gain, but I'm only 5'3, and the weight gain is noticeable because I have a small frame. My thighs start rubbing together and it's uncomfortable for me, and my clothes don't fit as well.
My boyfriend on the other hand is 5'11 and approximately 260 lbs (he won't tell me the number). He now wears a 40" waist in pants (he was a 36" when we met last year), for an idea of his size. He is extremely uncomfortable and ashamed that he is heavy, but refuses to stop drinking soda or eating fast food 3 meals a day. I love him and don't care that he's fat, but it is starting to cause a strain on our relationship because he gets in a horrible mood whenever he looks in the mirror or can't fit his old clothes.
So the issue is that whenever I spend time with him, he continues to eat poorly, and in turn I eat what he's eating because he pressures me to, and so we are both unhappy at the end. We would like to move in together in a few months for our jobs (right now we see each other for about a week every month and a half or so. We are long distance because we are pilots at different airports; he's just been hired by an airline and I'm an instructor but I've found a good flying job near where his airline is based) but I'm terrified that living with him full time will cause my eating habits to degenerate rapidly, and for his to continue to be poor and very bad for his health.
He tells me I should help him eat better from time to time, but will not listen to any advice, so I just don't know what to do. I want both of us to be healthy... my habits should influence his and not the other way around. His parents share my sentiments, and have talked to me about it because they are getting worried as well. But I am unsure of how to enact that change, and so I am looking for suggestions. My willpower is usually strong, but as soon as he wants to open an 11 oz bag of m&ms or eat an entire container of oreos I'm right there with him, and it scares me. I also notice I stop going to the gym when he's around. Sorry this is so long. I don't really have anyone to talk to about it in real life because it's such a sensitive topic. I hope this is the right forum for it.

