"Hey I need you to come watch me get my nails done while I plan out a night with my girlfriends" "well how bout I just don't watch you play video games then?"
Or "hey this isn't fun, I hope you aren't leading up to making me watch you jerk off."
Or just "I don't want to make you feel bad but I don't enjoy watching you play games."
I'd say be honest. He probably just wants to share something he enjoys. Unless he's a weirdo and it makes him feel extra manly to make you watch him succeed at doing nothing. I feel like you might equally ask him to listen to you read out loud to yourself even though he doesn't like the book. Mm seems more childish this way.
Tell him, ' My dear gamer boy, you maybe best and the coolest gamer out there, and I am glad that you enjoy gaming, but I don't see the point in it and I don't like to watch gaming. You can play and enjoy game as you want I have no problem but I will rather do something else, ' the thing is he needs gamer chick a gamer girl. Or he needs to be adaptive. To do things with you that you enjoy too
You: "I get extremely bored just watching you play video games".
Pretty simple. Either get interested enough to play (if you want to) or do your own thing while he's doing his. Just because you're dating that doesn't mean that every single hobby has to be done together. A bit apart can be good sometimes.