I can understand him thinking that the three/foursome continues into the morning and that it was okay to continue doing things even if you are asleep or not in the room. It doesn't sound like you discussed that particular ground rule before things started. So, just make clear to him that this is not something you are okay with (which it sounds like you now have). It's natural for you to be upset/jealous about the times in the past that this happened, but try not to be too angry with him about that, since that rule was not established yet. If in the future he does the same thing, then that is a major problem.

As for bringing the same person back multiple times. This can definitely cause problems if one of the partners starts to feel jealous. There is nothing wrong with setting up a ground rule of keeping it to one time - or even something about communication afterwards (no continued flirting texts).

It's also possible that jealousy is too big an issue to continue doing threesomes. But your boyfriend should make more of an effort to make sure you aren't jealous. It sounds like he is getting a little overly excited about adding others to your bedroom and isn't taking your feelings into consideration.