I remember being friends with some chubby otaku girl in highschool, she would just do that, just tell me ''anon i'm gonna masturbate for a little'' and do it on the couch when her parents were working and we were watching fucking gantz, she would put her head on my lap and masturbate without doing any sound, she was kinda smelly so it didn't turn me on, but me also being a degen didn't mind her doing that since I liked to watch hentai online too.
One day she decided to take her top off and I got a hard on, she quickly noticed and said ''EWW GET OUT!! GET OUT!!!''. Before that moment I thought she would be willing to fuck if I asked based on how horny she would get, that day I understood she didn't see me as a man, just as some kind of super gay friend or something, fucking stopped talking to her after she asked for an apology the next day.