The bride wants a joint party. There are two bridesmaids and one groomsmen. So there are 5 people and three people are paying. The budget is about 350 for the whole party. A little over 100 each person. Have any fun ideas?

I'm the bride and my closest friend ever is a guy and I want him to be one of the groomsmen. My fiancé doesn't want him to Bc he wants to pick other people. I understand wanting to pick other people too because the groom picks the groomsmen but idk why he can't pick all his friends and then I add in my best friend. Idk if this is a thing that people do but I don't think it's that weird to include a bride's friend as a groomsman? Is it unfair of me to think it's okay for me to pick him to be one of the groomsmen since the groom picks them? What should I do?