Everyone can do their kink the way they want to but one of my hard limits is the unwelcome threesome- that is when someone suggests to me that if I want to play (or sometimes even talk) with them, that I need to go ask a third party.

I don't accept that particular term, for three essentially three reasons:

Firstly, I expect that if someone comes to talk to me about play that they have either the autonomy to negotiate for themselves or the consideration to do the work for me. If someone wants to play with me and they have a rule that says they need to check in with their owner, then they should do so. The emphasis here is on they need to do so. I'm not going to talk to them for you. If playing with me has value, then this should be something the bare minimum.

Secondly, it makes actual negotiation very awkward. This is not a minor issue, but a major one. If I'm not comfortable in a negotiation then it increases the changes that at the very least, it will be a bad/boring scene, and at the most, that the scene will go very wrong. Clear, honest flowing communication is part of a good scene, and if I don't feel I have that, then the rest won't follow either.

Third, an I'm not in your dynamic. I don't respond to titles from people who aren't in a relationship with me. It cheapens the value of those words and the value of my relationships. By the same token, I don't engage in other people's relationships. I don't generally call anyone "Slave" or "Master", because those are terms that are personal to them and not to me. Requiring me to do an act of kink with a third party is one step too far for me.

I know that everyone has different limits. This is one of mine.