Neutered and litter trained male peeing on sofa

My 2 1/2 year old neutered male has taken to peeing on the sofa
He has a litter tray in his cage and another litter tray in the living room and he uses both. He hasn't peed anywhere else apart from the litter trays and now the sofa. He has only just started coming on the sofa, he previously just hopped around on the floor. He will jump up on the sofa and climb all over us and have a bit of a fuss and then he'll just jump off our laps and pee on the sofa. It's not in the same place every time and it's never a 'full' pee as such and when we move him off the sofa he doesn't carry on peeing. He only has access to this end of the living room when we're in so we can keep an eye on him. When he's sat on the rug he'll hop down to the litter tray if he needs a pee so I don't know why he keeps doing it on the sofa. Does anyone have any thoughts on why he would be doing this and how we could try and stop him?

Bunnies tend to like peeing on soft things, a few of mine do and they're litter trained.

You could get a clear shower curtain to put over the sofa cushions, or give him a litter tray on the sofa so he can go in that, but in my experience if they want to pee on the bed/pillow/towels then they do!

We don't let Poppy on the bed the same day it has been washed because she pees on it to put her scent on again I think, when we leave her we put a waterproof bed sheet over the duvet and pillows so if she does wee if won't go on the bed.