his penis won't fit

my boyfriend and I have been going out for almost 2 years now and we still haven't had sex. we both want to do bad but his penis doesn't fit in my vagina. does anyone have any clues that will make it easier for us to make it slide in. we want to share this together. also does anyone know anything on how to not make it hurt so bad because I know when we do it. it's going to hurt a lot!!