Cat Peeing on Baby's Things

I have two cats (5 years old, brother & sister) and a 7.5 month old baby boy. Since my baby started crawling, I have a mat, a bouncer and toys on the floor a lot. My boy cat has a history of peeing on things on the floor when things are cluttered (like when I was moving and there were bags and boxes on the floor, pre-baby). And he's very attached to me so when I had the baby, I wasn't giving him as much attention as I had before the baby. I've been trying my best to have one-on-one time with my cat and snuggling and feeding him treats and making sure he feels included in things with the baby and other things we're doing. Sorry for the long rant but I wanted to give enough background. Over the last 4 months, he's peed on the baby's rug in his room 3 times but has since stopped. He also peed on the baby's mat twice but has since stopped. Then he peed twice on the baby's bouncer (most recent time this morning). We're going to be putting up a big playpen for the baby in the living room and we want to be able to keep the mat and toys on the floor since it'll be a lot to dismantle and pick up every day. Has anybody dealt with this and have any tips to help my cat feel more comfortable or not pee on things on the floor? Any help is much appreciated! I want all my babies to co-exist together happily and healthy :)