I'm going with my gut and say that Jay cheated. B must have already known about it since she was very calm and collected, but Solange, like any half-decent sister, couldn't control her emotions upon hearing that horrible revelation.
I hope I'm wrong though.
I don't see how Beyoncé didn't react, but I trust that Beyoncé reacted strongly at home. She probably told Solange: "I'll deal with you when we get home."
OMG!
I still can't believe what I just saw.
But to me it looks like Solange might have some serious ****ing issues and Beyonce and Jay Z are used to this from her and are letting her go off OR Jay Z did something and Beyonce is staying out of it.
You know as soon as the paps stop following in that car, Bey probably gave Solange two shots to the dome and couple body shots. The queen has to be aware of her surroundings.