Seriously, you have your answer. If the person you're in a relationship with is just your girlfriend well, they come and go. If it's your wife well, they come and go too but when they go, they take half your $hit.

As Bill Clinton would say, "I feel your pain". But on this one I would take a pass. Too many red flags:
Religious - you'll have to explain to her every day why she's not going straight to hell.
Virgin - if you've never done one it's not all that fun until several months later. By that time you could be homeless and jobless.
Age - you have nothing to talk with a young girl about besides tapping that a$$. It's almost painful to try.
Significant other - see first paragraph.

However, if you do hit it take some photos and share with your Pelican brothers. Young girls love posing nude!

:D