Friends messing with friends...there is no way she is that bat shit crazy and if she is, it is already to late. She has your email, phone, and address by now I am sure. Although, if she has equally smoking hot friends and is willing to let them "into" your relationship it might be worth a go.
Party Foul! Dude - small "x", otherwise too easy at a glance to confuse with that fine fellow from the recentlyish departed MTV spectacle "Pimp My Ride" To recap: 2xIDB, or the more colloguial 2xidb is preffered. To capitalise the "x" is to throw a wrench in it.
You're not considering the most important part here... Can she put on/take off tire warmers? Work a lap timer? Make sammiches? Pour gas in a fuel tank? Perform other normal pit bitch duties? May be worth the crazy... Just sayin'.
Condoms are not even close to a solution for this "head on train wreck" just waiting to happen! Full on loon with a case of "baby rabies" Run, swim, fly, drive, sail, and then enter a witness protection program- and START NOW!!!
This will take some preparation. 1) Rent a wood chipper, the kind you pull behind your truck like a trailer. 2) Park the chipper under your bedroom window. Leave it running. 3) Get her in the bedroom and do her 2xIDB. Second time, grab her hair and say "You know, from this angle, you look just like your mom!" Hang on for some rodeo sex. 4) Toss her out the window into the wood chipper. Drive away, dump chipper into a lake, move out of the country, change your name and appearance with surgery. 5) Post up here with pictures.
If you think your buddy put her up to this, reply to her that you are interested in a 3 way with her and your buddy as you are secretly in love with your buddy and plan on expressing those feelings soon, during the 3 way.