beard burn??? down there!!!

I really love my boyfriends facial hair when he gets to grow it out he looks all scruffy and I like the way it feels against my skin. But last week he ate me out with some pretty good stubble going on and now it hurts????? Down there???? Like having a rug burn on your lady bits. I put coconut oil on it and that seems to have helped a little but is that normal or could it have been something else? Please help.. I'm honesty scared that it could be something more serious.