Quoting First Time Momma(::" His phone is back on... But still didn't answer. Tomorrow when the LO and I get up we're leaving the house for the day. And I won't answer when he calls or texts!!"
I'd be so tempted to do this if i was in your situation, But i garantee he will turn it on you, And it will only make matters worse, He wont see it as you 'teaching him a lesson' and showing him how he made you feel, He'll see it as you being a hormonal bitch, And probably walk out then and there and pull the same stunt again just to spite you.
Personally i would talk to him, Tell him how you feel, Tell him it's not acceptable, And tell him if thats the life he wants to live, Free and clear of responsibility to his partner and child, To pack his smurf and leave.