Why would a male invite a female colleague out to lunch when his girlfriend happens to be there as well?

[Anonymous]

I was working with my boss's girlfriend yesterday as there's a lot to do for opening a new business & afterwards he made a quip about all three of us going for lunch. I accepted. We had some decent chats.

I am more curious why he invited me though... like why guys would you invite a woman to dine with you if you've your girlfriend. There was no reason for him to invite me really.

[DonkeyDan]

Maybe he just thought the 3 of you would have a nice lunch together, why does it have to mean something?

[Asker]

It doesn't need to mean something just a bit odd, I suppose.

[Anonymous]

threesome or he plans on cheating on her with you