Every time after intercourse my vagina burns. i don't you condoms with my bf. i thought it could've been my lotion from my skin or lube but it's not?

Vaginal Burning: it sounds like you having tried eliminating most things that can cause burning with intercourse, even using lubricants. It is possible that you have burning from friction but that would be unusual especially if you even use lubricant. Some women have an allergic reaction to semen. You could try intercourse with a condom so there is no contact with seen and see if that is the cause.