Very reluctantly. He felt guilty afterward, so I cannot imagine that he will ever do so again, though I made that offer as well.
[She reaches a hand up to her neck, the spot where he had sunk his fangs into her.]
I had a mark on my skin for several days, but it has healed. I visited the hospital at his request, but they said that I had not suffered any effects.
[She'll just leave out the part where Zero told her she could have very possibly turned because of that if he had been a different kind of vampire, which she didn't even consider before she blindly offered him her blood.]