need advice

What to do when your mother in law is too involved in her sons life and our relationship...but when I speak to him he says I'm jealous of his mother...I just need to know what to do...we are having a argument right now and I said I am here just for our children...and he said to stop doing anything for him so I said fine...little to my knowledge I start seeing his mom that is visiting from America cause we live in Jamaica,keeps coming in our room cleaning up his messes,washing his clothes,picking up his dirty clothes and plate he throws all over the house,when we argue she is quick to say "so if she wants to leave let her and he runs to her about every problem we have, even when I say don't do his or don't give them that to our children she still does it but when he says it she respect his wishes...I'm annoyed and frankly over it...what to do????