[Trigger Warning] My female flatmates masturbate too loudly

Hi all, from this september I got 2 new female flatmates and in just 3 weeks time I heard one of them once and the second one even twice masturbate. Moreover the second one was so loudly yesterday that it was like if I had played audio of porn on my computer. I battled with myself obviously my dick rock hard but at the end I managed to play some music and stopped hearing it. It was only 3 days in my challenge but I am seriously worried what would happen if I have 30 days or so.

Any ideas what I should do? I consider it kinda unwanted P-Sub, but i dont want to tell them I am doing NoFap.