I (f23) caught my bf (m25) doing something gross

My bf (M25) and I (F23) have been together for about 2 and a half years now. I discovered something he does that I think is disgusting. After he finishes masturbating, he eats his own nut. I have insomnia so it takes me a really long time to fall asleep so I think he thinks I am sleeping when he does it. I don’t lay there and watch him, but I can obviously tell what he’s doing. I don’t know how to bring this up or if it’s even a big deal. How abnormal is this? How do I bring this up in conversation?

EDIT: when he KNOWS I’m awake while he’s doing it, he gets up to clean up afterwards. He never does it knowing I’m awake

If you think I’m kink shaming, you’re wrong, I have an opinion and personally do not enjoy eating it. I’m trying to learn more. I think this is more laziness than a kink anyways.

To those asking why he’s even masturbating in the first place, I’m a woman who gets a monthly period and he doesn’t wanna touch me during that time since he’s so grossed out by it