You aren't being unreasonable, you should be able to do the same as him and if he is away 5 nights a week the maximum you could is 2 nights (and you probe wouldn't even go out then) so that's really not 50/50
My oh works 8-5,
On a we'd he has football 6 - 9
Football game sat 12- 4
He is also regularly asked to play for 5 a side games if they don't have enough players, I tell him I don't mind every now and then but make it clear I don't want him having another weekly thing that's set in stone.
He also has the gym - pre kids he'd go 3 nights a week, now he goes in the morning or not at all as he doesn't think it's fair on me.
He goes out for his friends b days, head wetting etc but has made it pretty clear he can't go out every sat night like we used to
So I'd say 3 different times a week is probably as much as I'm happy wit, anymore and I start feeling a little neglected and taken the piss off.
I go to see a friend once a week or every 2 weeks, go out for a meal with them around once a month