I got my bun when she was 8 weeks old, she is a year now. before she was old enough to be spayed she hopped on my couch where I always sit and she would pee. I cleaned it up and she would do it again. my vet told me to clean it up but to put something on the couch cushion where I sat that had her scent, this stopped her from peeing. my vet told me that my bunny knew I was her owner but wanted to show me that she is the top bunny in the house, your bunny keeps smelling your scent where you sleep so he is going to keep peeing there. have you litter boxed trained him yet? I trained my bun in a matter of day’s. as for keeping him off your bed, you are just going to have to keep him out of the bedroom until he is neutered and litter boxed trained. my bun has a blast playing on my bed at night with me, thankfully she doesn’t pee on my bed or anywhere but her litter box.

I agree you need to keep him off the bed. He marks it because it’s a high value place with lots of your scent on it. I built a cage of compost grids around my bed when my bun was new with me. Now I’ve taken down half the grids, my bun seems to have forgot the bed is even an option so he hasn’t jumped up on it.

Meanwhile a plastic shower curtain could work, not a soft “textile-like” shower curtain, they are too nice for the rabbit to hang out on and they let pee through.