I only know how to chew gum and kill my twin brother, and I'm all out of gum. This story makes me sad. I've been told so much about the true and special relationship between twins, apparently involving sex a lot of the time. I'm not sure what that has to do with Dante and Vergil constantly trying to kill each other; I'm guessing it's foreplay.
I have this advice for you two: practice safe sex. Put away those swords, and get yourself some Nerf bats or something. Otherwise, tragedy could result. Namely, mpreg. (If you want to know what that is, ask Wiccan. I wash my hands of all responsibility.)