Firstly let me clarify that I’m not a fan of Twilight. I think the movies suck. However, I have always been infatuated with vampires, thanks to Anne Rice.
I’ve always thought being a vampire is cool, despite its challenges. A vampire loves unconditionally and is always in need of an eternal companion. They are, after all, immortal. You can’t live forever alone ’cause that would suck (pun not intended).
A vampire is also beautiful. He is charming as hell. He is strong, can move fast, and has heightened senses (both physical and emotional) compared to a human. Some can even fly (it is aerodynamically possible if one moves fast enough). A vampire is a compassionate creature. As much as they need to kill humans to survive, they would rarely attempt to harm their own. They do not need to socialize in a large group. Rather, they usually enjoy the camaraderie of a close-knit social setup.
A werewolf is wild. She is ferocious. She may be beautiful in her human form, but once she turns, she’s no better than a rabid dog. She would lose her common sense then. She would kill at will… indiscriminately. She has little to no compassion. She would not hesitate to fight even her own kind, although werewolves are generally gregarious and live in a rather large pack.
So… can a vampire be with a werewolf? I would not say that it’s totally impossible, but it will be an arduous task. The two are quite the opposite (other than the fact that both are cursed and would face eternal damnation in hell).
But love is blind and as a hopeless romantic, a vampire can fall for a werewolf, falsely believing that things can work out between them. A werewolf is not that astute, hence she accepts the courtship without really thinking it through.
Things can be great at first, but several years down the line, conflicts will arise, arguments ensue, hatred spawns. Before you know it, things have turned to shit.
At this point, the vampire is starting to realize that he would have been better off with his own kind — someone who actually understands him to the very core. But it was the werewolf who came to this conclusion first.
Naturally impatient, a werewolf just cannot stand the vampire’s lack of urgency. She would be easily agitated by his every move and mere presence. Still very much brutish, she instinctively wants to beat the vampire to the ground — crushing his spirit in the process. She rekindles with her pack, leaving him feeling very lonely and longing for a companion.
So in conclusion, I do not think a vampire can be with a werewolf. It would take a whole lot of effort in surmounting the personality clash. It’s gonna be an energy-sapping struggle in reaching the seemingly unlikely equilibrium.
But what drives the final nail in the coffin (again, pun not intended) is this: A single werewolf bite can kill a vampire. So go figure.