Moving in together ?

So my boyfriend and I have been together for a really long time and marriage , and all that good stuff has came into picture and we've been talking about it lately ... But now he's saying he's moving in with his friends first , then when we get married I can live with them? Am I completely crazy for thinking that I shouldn't have to share my boyfriend or a house with his friends when moving in becomes a option? Because im now im just on the verge of leaving because I don't think he's ever going to grow up .