I recently met a girl on tinder. After talking to her a bit, she said she had a BF and that they we're looking for a 3rd guy to have some fun with. So how does this work? Do I game her like every mono girl? Take her out on date, game her, meet her bf, drinks, go back to their place, and fuck? I'm super confused about the dynamics. Can someone more experienced with 3 somes please clarify?

EDIT: thanks for the help guys!!