rocky started weeing on floor

One of my male rabbits has stopped to some extent using his litter tray when he's in his playpen at night. He is 2 years old neutered. He has always been a bit hit and miss when it comes to pooping. My female who lives with him rarely poos or wees out of her litter tray but recently rocky has started weeing on the floor. His wees look ok, normal colour etc and I haven't moved the litter tray or anything. Has anyone any idea why he would do this.

Just putting this out there...no proof it'll work but maybe wifey bun has claimed litter tray as her sole domain. Do you think it worth adding another litter tray if possible? :wave:

Thanks yes good idea bluebell does not like sharing her litter tray so maybe its that. Plus he keeps trying to hump her at the moment but she would never allow it and grunts and growls at him. They never hump she won't allow it I wonder if they struggle to work out who is dominant as they both seem to be?