The door to biting had been opened long ago. But, Lisa had to be careful because Fleur didn't heal like her. Too many bite marks, and questions would be asked. Fleur, on the other hand, could bite all she wanted!
Using her 'human' teeth was her alternative.
Pulling away from the kiss, mostly to see what the blonde would do, Lisa felt the stirrings of a first orgasm. Pressing back against the Veela woman, she spurred them closer.