I was wondering how to wean out the people you are dating who may not be polyamorous and just want to have group sex?

Your best bet here is just to ask clear questions. For example: What are you hoping to get out of this? What’s your best case scenario? What have you learned from previous poly experiences? If they say things that seem disingenuous or seem like red flags, you can ask for clarification, or point out where your desires/expectations might not align. 

Of course you don’t want it to feel like a job interview or an interrogation, but most people are happy to talk about themselves if the situation feels nicely conversational.

Whether you’re going into group sex or a poly dating arrangement, it’s crucial to have open lines of communication and know where all parties stand, so if they’re not willing to have this conversation, that’s an early signal that you may need to back out.