Nope. Your ah shouldnt volunteer you for something without consulting you first however People make mistakes and perhapse because of your caring nature and involvement with your friends he assumed it would be fine with you. An assumption that was incorrect and a mistake made by many including myself with my ah as I have volunteered him and made arrangements for us before and realized my mistake after.
Were all human. That happens in relationships furthermore its different to not care about other people or their problems until it hits closer to home ie your friends vs his.
This may be a learning curve for him 1. His friends have gone through things and hes involved so he needs to learn to understand your involvement with your friends and 2. To consult you first hand.
In my opinion I would make a simple small meal for them (even before dinner time and bring it up there when you can. Its for them not your ah) if you can and then afterwords affirm to him to communicate with you first