Cat peeing vent. 😟

Okay so. Have 4 cats. One is a boy. He has recently just started pissing all over any clothing left on the floor and the couch. Iv taken him to the vet and everything checked out fine. I just dont know what to do. I spent the past weekend monitoring the couch because i had family up last weekend. He is a mamas boy and i just dony know what to do. I love him to pieces but I dont know how this will be with baby in 5 weeks. 😟

I have tried almost everything. Added a litterbox. Switched litter, added a calming diffuser scrubbed my couch with baking soda and peroxide. Even used vinegar.

He is neutered as well