My bunny repeatedly pees on my bed

My fiancé and I got a mini lop male rabbit named Oreo. He's around 4 months old. And we let him roam the house every now and then. Once Oreo discovered he could hop onto our bed he pees on it. We have to keep a close eye on him when we let him out now because the moment we look away for a minute he will hop onto the bed and pee on the bed. I need help and advice! Why is he doing it and how can I put a stop to this behavior?

Rabbits looovvee to pee on soft bedding -- especially hormonal bunnies! He's about the right age to get neutered and that helps buns to establish good potty habits. As for the bed, if neutering doesn't stop that peeing, then you'll need to barricade the bed.

Trying to train a hormonal rabbit is usually a fruitless effort. Once he's fixed (can take up to 8 weeks post surgery before hormones fully dissipate) then he'll likely be better about potty habits and may stop peeing on the bed.

Dominance and marking behavior for sure. Our 1st bunny loved to "dig" on our new couch, so I put boxes on it when it wasn't in use. She'd still lay on the arm rests or the back but couldn't get to the cushion/dig site. Sometimes neutering does help, but vigilance is a must.