Cat wont stop peeing in the bed

We've had this cat, willow, for almost a year, and we've never had issues with him peeing on the bed before. But in our first apartment with him, we didnt let him in the bedroom at all. We recently moved and we had to move in with my girlfriends parents in between apartments, the cats stayed in one bedroom the whole time we were there (about 2 months) and had no issue with peeing on the bed. In our new place, which we moved in about 6 weeks ago, we have a yard. We thought it would be a good idea to try to bring the cats outside with harnesses and leashes because they always seemed to curious about it. But the day we did that, my other cat became aggressive towards willow, so we stopped taking them out. Pretty much ever since then, willow has been crying and crying by the door and tries to run out every time we open it. Hes gotten out a couple times, and when we track him down and bring him back in he almost immediately pees on the bed. Now I've been told that cats dont retaliate, but I dont believe it. There is no correlation to the pee besides us making him come back inside. The litter boxes are scooped regularly, they have tons of space and toys, the bedroom door is always open. Willow has also showed no signs of urinary issues. When she doesnt pee on the bed she uses the litterbox just fine, doesnt seem to be in pain, and doesnt poop anywhere besides the litterbox either. Willow has pissed about 4 times in the last week and we are at our wits end. My girlfriend is ready to find a new home for him but I desperately want to find a solution so we dont have to do that. Any advice would be wonderful