Father Going Against Verbal Agreement for 50/50 Custody

My question involves a child custody case from the State of: ny..my sons father and i came to an agreement that we would share 50/50 custody of our child so he could add him to is lease in order for him to obtain a bigger apartment in his complex..after writinghe notarized letter and him moving in he now spends no time with b our son..Stating thank you thats all i wanted from him..my question is what if any action can i take to jave him removed from his lease due to him going against our agreement?

We know nothing about your husband's situation, or why you believe that his landlord would deem it a breach of his lease if your son lives primarily with you. Odds are you have no power at all to affect his lease.