Jagz, when you girlfriend said that she needed time to think, it may be that she needs to think and sort out your reaction to find the best way to define her position and make you understand her without any hurt. Your GF may have been very confused by your reaction and was surprised by the intensity of your hurt. That places her in a position struggling to determine whether what she did was right or wrong.

But, your GF had no ill intentions and what she did was extremely normal.

(and a guy throwing around girls? Yes, that's hot, lol.)