That is when you have blackmailed Vanessa, and while she's blowing you in the cafe, the old customer guy is trying to get service and being a dick about it. To get the scene, you have to be rude back to him. The reason being, the young woman from that couple at the beach is his granddaughter.
It's complicated, but yes, you can be with Ann and still do stuff with Vanessa...but technically, according to TTrick, to be on Vanessa's path, you have had to gone to the bar with her instead of Ann early on. If you go with Vanessa early on, you can still become Anne's boyfriend. There is a setting in the game that indicates whether she's late girlfriend or not. And on the same token, if you're on her hate path or late hate path. It just depends at which point you accept her/reject her.
Either way, the choices made determine what content you get. For example, you can't get the threesome with her and Ann if you blackmailed Vanessa.
