How would you react to your girlfriend secretly accepting a guy's facebook at a party?

[Lars]

I took a girl I have dating to a party. A guy tried to slip her his facebook information without my knowing. She also didn't realize I'd seen it. After the party, I asked her for the note. She responded in a guilty tone, "You saw that?"

How would you react to this? It is still early in the relationship, but I sense that she may not be trustworthy now.

[CAB]

She's already shopping around for better options.
You should preemptively dump her.

[Waterdragon]

i would be so disappointed that she is tasteless enough to have a FB account --- i mean ewwwwww they have to be the epitome of bad taste

[skaterdude]

she asked if you knew about it so that means she was trying to keep it secret, so either dump her or tell her to cut the bullshit