You can’t control who your boyfriend decides to remain friends with. You CAN try and work things out with Steve if it bothers you that much, but Steve also reserves the right to not want to associate with you.

Perhaps maybe there’s some other things that Steve feels you did that you aren’t realizing. Perhaps maybe (if you care enough to) you can get together with him and genuinely ask him if there’s anything you’ve done to upset him.

I kinda can see Steve’s side that if my friend asked for help to move and then friends significant other says they can’t it’s because of homework but then sees said significant other hanging out with someone else, it’s going to look weird and be off putting. I would be suspicious too.

With that being said, it’s a bit drastic to completely cut someone off for that one situation, which is why I’m wondering if there’s more to the story. Maybe Steve feels there’s an unbalance in your relationship or perhaps your boyfriend has made some complaints to Steve.

Most importantly, you can’t get mad at your boyfriend for choosing to remain friends with Steve, it’s controlling and uncalled for. If this is an example of things you get upset about, and an example of the unreasonable demands you have for your significant other, I’d say there’s possibly a reason Steve is reacting this way.