Last night DS (age 3.5 years) woke up at 3am and wouldn't go back to sleep. He had gotten into our bed and when he became so noisy that we feared he would wake DD (5 months) DH got up to take him back to his room. The bedrooms are right next to each other and I could hear them even though DH had shut the door. DS wouldn't settle. He had his first school trip today and was very excited. The situation escalated until DH became quite confrontational and, in my opinion, quite bullying. He started telling DS that he would call his teacher and say that he couldn't go on the trip if he didn't go to bed. DS of course became more and more frantic and I heard him get up and try to open the bedroom door. Then DH must've picked him up and put him back on the bed a bit forcefully from the sound of the bedsprings and the fact that DS then started screaming.
I couldn't take it anymore and got up and tapped on the door. When DH answered I said "I can hear you and it sounds like you're being a bit mean.' I admit, I should've chosen my words more carefully but felt quite shaken and upset by what I had overheard. DH then stormed off to the loo. I tried to calm DS and explained that everyone was tired because it was the middle of the night. I didn't want to undermine DH.
DH came back, still angry, and said he would be sleeping elsewhere and then stormed off to the sofa leaving me to deal with a distraught DS. We've had almost the exact same situation before and DH accused me of trying to be the good guy and make him the bad guy. That is absolutely not true but I don't think I should just stand by and let him bully DS. I've certainly had my own regrettable moments with DS. It's usually when DH is travelling or working late and I've reached the end of my rope. If DH was here I would hope that he would intervene. I've told him this but he doesn't believe me.
Am I overreacting? Is DH's behaviour acceptable? How could I have handled this situation better?