8 year wait

So I've been with the same man for 8 years on Oct 17th were pretty young I'm 23 and he's 24 and we have one 7 month old together so why is it that I can't seem to get him to marry me i get that were young but damn I know what I want do you think its possible he is scared still after 8 years or do you think its me maybe he doesn't want to commit that much so he can still run idk its driving me crazy and everytime I talk to him about it he just makes it into a joke or doesn't answer me idk what to do anymore I'm getting very tired of waiting advice?