(2X6/2X7 Promo) When Bonnie Says "He's Küssen Her, Elena." Who Do Du Think She Was Talking About?

I'm a little confused about this because in the 'vision' they Zeigen in the promo, Katherine is with Mason and then they Zeigen another another when she's with Damon... I think Bonnie tells Stefan she saw Elena Küssen both of them...
I think Bonnie doesn't believe for a Sekunde Elena would KISS Mason but my guess is that she was kinda worried because Damon and Elena would kiss, I mean, she sees something between them.

She meant Mason.

Of course Mason.
and how is she supposed to know who is Kat and Elena

She meant on Mason. But then Stefan told her that is Katherine,not Elena :D