Sex with my boyfriend

How come every time me and my boyfriend has sex on and off within hours he tells me that his penis is starting to sting going in because it’s really tight ? Is there something wrong with me down there ? Plus I know I feel pain during us having sex sometimes too after he goes in and don’t go back in for a while and I get dry why is that ? Although , even though I feel pain during sex sometimes i never wanna stop because I still feel a bit of pleasure