When I was a student many years ago, there was one girl on our corridor in our hall of residence who had such strong BO that you could smell it out in the corridor when she was in her room, ans she left a long lasting trail behind her in the communal areas. I was the mug who was deputed to speak to her. After tying myself up in agonies of anxiety about hurting her feelings, I said as gently as I could to her that there was a bit of an odour from her underarms and maybe she needed to change her deodorant. Her response was to inform me that she liked the smell of sweat! And she carried on smelling.