I wonder if it has something to do with what he is eating... What your bf eats can affect his sperm.

I use to be like that a few months after my bf (now fiance) were having sex. It was more like friction because we weren't using condoms and I was on the pill. Eventually it went away because we started using lube. Like alot of it. For me it did burn when he ejaculated in me and for about 20 mins afterwards. Did u check down there to see if there was any kind of irritation? Mine was red down there around the opening of my vagina after sex.

I think it is probably raw skin caused by friction, and the fact that then you're putting a salty mixture on raw skin: semen has salt in it.

yeah that's what my doc told me. So just try using some lube, it really helps!

with me happens the same burns when he comes but only when im close to my period before that everything is normal

it because around your period your vagina is drier that usual. try using lube it helps