What would you do?

Soooo my child’s father has not seen him since March 8th he hasn’t even asked about our son.

He just messaged me asking if my sone is busy tomorrow because his mom wants to see our son.. not because he wants to?? (He lives with his mother)

I just got into a fight with my spouse because I said what am I supposed to do keep my son away from his other half of his family? And my spouse said well if my son comes back an ass hole it’s my fault (he always mis behaves after seeing his grandma and father)

I’m just at a loss on what to do..

I will add that we do not have a custody arrangement, my son is 2 1/2, my ex has never helped out with my son emotionally or financially. I have raised my son alone and am the sole caregiver.