Fifty years, huh. She's younger than he would've assumed, most vampires in his experience rack up a century or two of murder before they have a crisis of conscience. Usually involving some mortal friend or what have you showing them 'another way'.

The surprise doesn't show on his face though, instead he laughs into his drink and nods, "lucky me indeed. It might be old-fashioned, but I'm quite a fan of keeping my blood in my own body."