I would have a chat with her if I was you, a cuddle can lead to a slippery slope, and it would be mental torture for you to be constantly wondering what it is she is up to.

It may wlel be that she is scared of commitment, 2 years is a long time, and she may well feel like a change and this is her way of indicating it. Alternately she may just be very liberal and flirtatious when it comes to being with the guys at her college, and enjoy teasing them.

Saying she will come back to you is very little comfort for you, so I think the best way is to tell her how you feel about it. She would be stupid to jeopardise a 2 year relationship for a kiss and a cuddle.