Swinger friend

So I’ve never encountered an experience like this before which is why I’m here but my boyfriend had brought up to me that a man friend of his from high school had said he’d link up with my boyfriend (who is straight) if I was okay with it. His friend is also in a relationship but I believe they’re swingers. Long story short this friend of his has declined any invites to hangout with our group and only wants to hangout with my boyfriend one on one. Should I be feeling skeptical?