Hello.
If you were in a small cage with a member of the sex you found desirable, wouldn't you be trying it on too?
I would say he'll probably keep giving it a go. Why don't you get one or other of them neutered? Unless you want a lot of baby bunnies hip-hopping around. Probably not so cute when your garden is overrun with them! And apparently not cheap to keep either.
If he "mates", as you put it, just the once, I am sure he'll keep on "mating". They can be around each other but if neither are protected then they will need constant supervision, and can't really "live" together in the way you are suggesting. Unless you find bunny condoms!
Two of my friends both have a pair of rabbits, both a mixed sex pair, and each rabbit lives separately, coming into contact with the other only for supervised play.
Lisa.