I know and understand how you feel.
I've been with my boyfriend two years nearly, and he's the only person i've slept with.
Sometimes i think, 'i'd love to be doing what all my friends are doing, getting more experience' but then i think 'would i really?'
I'm only 17 years old, as much as i love my boyfriend to peices, i'm not certain it's gonna last forever, therefore there will be plenty of time to meet new people, but whilst the relationship is still good, why finish it just to be with someone else?
You can't live your life with the attitude that the grass is always greener. Enjoy what you have. You've got a girlfriend who will have sex with you, i take it you both enjoy it, so don't think about what else is out there!
There is plenty of time for that...