I dunno… but I suppose she’s old enough to go out to a club with a guy she knows has the hots for her while her real boyfriend is elsewhere, and she’s old enough to get stinking drunk with this foreign guy.
If the foreign guy did indeed take advantage of her, he is an ass, and worse.
But, she demonstrated remarkably poor judgment, IMO, and if I were her real boyfriend, I might find this entire episode difficult to understand.
Nonetheless, I wouldn’t call her a “slut”.