[PJ]

Ehhhh I have to agree with fliptuner.
I wouldn't do it, personally. I would just straight up tell her it's not a good idea.

You sound young. Take it from me, always avoid getting into potential complications with friends and their gf's/ ex-gf's.

There's a bajillion girls out there that don't have any headache attached to them.
But yeah, you're young, hormones are raging. So do what you gotta do. Make sure you have your options properly and objectively weighed out, or you might lose your friend, or even both of them.