Male marking

Does anyone know if there is a way to stop a male dog from marking in the house? He’s a 2.5 year old yorkie (not fixed) and we’ve tried putting the belly band diapers on him but he ends up rubbing his belly on the rug so much that it slides down he can still mark on stuff, we have the spray cleaner that’s supposed to stop him from marking in that spot again but he still does. I asked his vet if fixing him would help and he said probably not much at this point. He really only does it at night when we’re asleep. I’m just trying to avoid having to put him in his crate at night but my husband is ready to get rid of him if we don’t figure something out bc he’s ruining things in the house. We let him out at like midnight or 1 am and then he goes out again around 6/7 am so it’s not like he can’t hold it he just chooses not to :/ and as soon as we find a spot he marked he puts his head down and walks away so I know that he knows better :( I’m a stay at home mom so I guess his crate at night wouldn’t be too bad since he’s out all day all the time.... if anyone has dealt with this and has any advice please let me know!