Do married men hate single men having fun?

My cousin is 32 and not married, he has a good job, works out regularly and looks decent. He’s dated a few girls before and also loves travelling and has been to 15 countries so far

I was talking to him and he told me how his friends who are married or married men are resenting him more and more like as if they had to succumb to the societal pressure of marriage and seeing him not do that is annoying to them

Do you agree with this?