Umm, if they're really close friends of yours then that's totally normal if they ask you, if not, then they're probably planning on making fun of you or gossiping. It's normal for you to talk about that stuff with both male and female friends if they're close friends of yours, but if not then it's very likely that they're just gonna mess with you.
Although, even if that happens, there's literally nothing to be ashamed of. Because you admitted to masturbating which literally just means you jack your wanker. It doesn't mean you watch research even though it's very likely. When I was your age, hell yeah I fapped, I didn't watch research though, I just wacked it like there was no tomorrow. Also I'm not saying watching research is bad, I'm saying that you only admitted to fapping and not watching research, fapping is really nothing to be ashamed about, while research kinda is if people pick on you about it.
So yeah don't feel bad about wackin' it.