I do not think it should be us you are asking. I believe you should be asking your girlfriend. If you relationship is trust-worthy enough, I don't see why it should be a problem --- and neither should she. You should also ask yourself --- "Do I trust myself in this situation?"
I would imagine that your conjecture will come after you've done those things.
"I still find each day too short for all the thoughts I want to think, all the walks I want to take, all the books I want to read, and all the friends I want to see."
- John Burroughs