Most Helpful Girl
It's a sexual act, but it is not intercourse. So no, it doesn't count as having sexual intercourse with another partner, but it does count as committing a sexual act with another partner.
Most Helpful Guy
If you weren't together when she did why bother? If she's still a virgin then it's not a big deal, but if she's already open, what makes you think she didn't fuck him? How long is it since you were together, if it were just within a week, then she's definetley one of them sluts? How do you like that she were able to forget you so fast etc...