I work with this couple and I have a really good friendship with them. She’s in my team, he’s not but I’m friends with him thanks to her.

She flirts with me a lot and even make sexual jokes with me (when I never make any). I was once having break with her boyfriend because she was off and I caught him texting with another girl. When I jokingly asked him if he was cheating on her, he laughed it off and instantly changed the subject of our conversation.

Do you personally think they might be in an open relationship? What can I do to find out if they are in one without directly asking them since I don’t want ruin our friendship if they are not in one?