People unfollowing me because I posted a pic?

My boyfriend and I been together for a year but have kept our relationship off of social media because of personal reasons. Today I decided to post pictures of us together and suddenly people that I used to talk to start unfollowing me right after I posted the picture of us together.. these are people that were friends of mine and know I'm in a relationship I'm so confused at why this would happen? Most of my friends that unfollowed me are guys.. what could be the reason?? I'm so confused..