So my ex and I broke up around 3 years ago. We only went out for 5 months, and it was a very mutual breakup. Now, he doesn't believe in being friends with exes, but I dont share that same belief. If the breakup is mutual, I am ok with remaining friends, or at least being respectful to each other. I understand that he doesn't wish to be friends, which I respect, however, some of his friends and I are still really close. They have mentioned to me on multiple occasions that they "like me more" or "have more in common" with me than with him. Anyways, these friends (lets call them Jane and John) are having a party and have invited me. Jane told me the other day that my ex is not comfortable with me coming since it will extremely bother him and his girlfriend. I dont understand why it would, and I was going to bring my fiance with me anyways (he doesn't have a problem with potentially meeting my ex). My friends still really want me to come, and say that my ex can leave if he feels bothered. Should I still go, since a majority of the people there will be my ex's friends, and not mine. Am I encroaching on personal space/boundaries?
Also, my ex and I have not spoken since the breakup.