It comes from simply having priorities that are not realistic on his part. His sense of sense and physique has become exaggerated to now where he needs it in a partner. He is indeed becoming shallow and this is a factor that will kill a relationship because he needs someone to feed his ego by looking a certain way. This is as you described it shallow. It is a way of standing out but puts demands on your that are not necessary. If you choose to stay and he doesn't come to terms with this then you will be worried about your image and genuine characteristics will become secondary. He needs help to put this in perspective and you have some decisions to make
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I see that you've re listed for an incomplete answer, I would like to attempt to help if that's okay.