Sex question

Okay, so I have a question. My man asked me what I was doing in bed last night (like in my vag) and I had no clue what he was talking about. He told me it felt like I was opening and closing something and he had never felt that before. It was a little different this time, probably the best yet. It was different thought because this time my clit was being stimulated also. Idk if that is tmi but I also don't know if that could have something to do with it. Does anyone have any idea what it is that he was feeling?