So This Only Seems To Happen After I Have Sex

So this only seems to happen after I have sex w my partner.. but my clit n labia become somewhat itchy n then I have this white residue around my clit n labia as well as if I whiped with some cheap toilet paper.. almost like little pieces of white debri or skin? not sure.. doesn't smell no discharge and it goes away usually after a week or so n I'm back to normal. Could I be allergic to the type of soap he uses or maybe even him? this only happens w him n right after sex.. Are we doing it to rough not enough lube idk