Name changed for this as it's quite specific.
Last night I was out with a group of mates, at an event where a couple I am friends with were also attending. Let's call them Bob and Margaret.
After the event me and my mates were going for a drink, I invited Bob and Margaret along. Bob was too tired but Margaret wanted to come along so Bob left and she waited with me for the others. Really I prefer Bobs company, although we have always socialised as a three. I decided to encourage Margaret to go home after Bob, and said I would see them in the week. She took the hint and went to catch up with Bob.
About 20 minutes later I got a text from Bob asking me that that was all about, and why I had treated Margaret that way. Margaret didn't contact me
Bob is the more extroverted of the two so I really thought it might be awkward or difficult with just her. She didn't look upset or anything she just said ok. They now don't want to see me for something we had planned this week.
I think I made the right call really and reckon I didn't have much choice, but now I think I have lost my friendship with Bob.