My male cat acting up?

If you haven't cleaned the spot where he first peed thoroughly, the smell of the enzymes will bring him back to that place. Try using Nature's Miracle, or some other specific cat urine enzyme remover. Let it soak down into the mattress till all the smell has come out, and wash your bedding with regular detergent and a nice healthy squirt of Nature's Miracle in as well. He's probably marking his territory from the girls, letting them know that that's HIS bed, and they're not allowed to use it when you're gone. I'd say take him to the vet just to rule out the possibility of an urinary tract infection or any other sickness that could be causing him to do this. Do you play with Oscar? He may need playtime, not just love time. Invest in a few fun toys (mine LOVE fishing poles and jingle balls) and take him to your bedroom, making sure that the other cats aren't following you (to have some one on one time). Cats need to be played with for about 45 minutes every day; this not only helps them bond with you, but also relieves stress. Build little obstacle courses for him to chase the fishing pole around, since it gets boring if it's just dangling there. Be sure you put the toys away when you're done with playtime, so that they'll seem new every day for him! Good luck!