You can start by making him responsible for himself and you being responsible for yourself. So, when HE invites folks over ask what He plans on feeding them! If he balks, gently, lovingly tell him that if he would like you to be involved in feeding guests, you would love that, as long as you are involved in the invitation process, as well. Give it a shot. And if HE invites some folks over, without consulting you...what about taking son out to eat and leaving him to deal with his party...on his own? Don't do it nasty, just say something like you had plans to go out for pizza with/child and aren't going to break them...maybe you'll see him and his guests when you get back. Tell him to have a great time and then, go! Or try some variation of that..
Makes him responsible for caring for guests he has invited..not you.
It's worth a shot, don't you think? Actions speak louder than words, so don't just talk about this...act on it. Then, if he consults you about having guests...go out of your way to make a good meal, nice snacks, whatever...and be a great hostess...that will positively reinforce him having consulted you.
Just don't walk away from his unannounced party plans angry...just walk away calmly and nicely. Let him know that HAD YOU KNOWN or BEEN CONSULTED...you might have been available to help him with his guests.
If he balks, gently, lovingly tell him that if he would like you to be involved in feeding guests, you would love that, as long as you are involved in the invitation process, as well. Give it a shot. And if HE invites some folks over, without consulting you...what about taking son out to eat and leaving him to deal with his party...on his own? Don't do it nasty, just say something like you had plans to go out for pizza with/child and aren't going to break them...maybe you'll see him and his guests when you get back. Tell him to have a great time and then, go! Or try some variation of that..