u/Cold_Tomatillo_837

I have noticed pink colour small bumps (painless)on my laiba minora after rubbing clothes or after mustarbation (rubbing that area for like 15min)and if I continue rubbing it over that small bumps then it'll turn red and after that when I touch that bump I feel pain (only when I touch) but that condition never went back to normal condition.but if I don't touch that small bump , it'll stay same like no irritation no pain nothing,so what is it and what should I do?