you have literally nothing to worry about in terms of washing. between the water, the soap, the friction and the sheer unlikelihood of it all...you are FINE. think about hospitals and daycares and stuff...no one gets sick from laundry.

on a side note, ew on the dude not washing sheets or anything. I dated a guy like that years ago...every few months he'd go to ikea and buy new sheets. we dated for a while and I literally had to train him to strip his sheets every two weeks and wash them. NASTY.