Explore options or settle for the one? Watch
If a girl (or guy) ever says this to you than they don't truly love you/want to be with you.
I think exploring more options would be the right thing to do since she clearly is curious and will remain that way until she meets other people. If she really is the one then I'm sure she'll come back to you (and you'll live happily ever after). Meanwhile - you should do some exploring too!