Laz had been with his fair share of women before, there is nothing to be said about that. Most of them were unique in that each one had a different feeling and a different flavor. It didn't matter who it was, each of them left a unique brand in Laz's heart, much the same way he left a unique brand on their bodies, something he didn't even know about himself.
As for why that was, it had to do with many factors, not the least of which being how they reacted to his bloodline. But the largest reason was something else, something far simpler and more primal.
It had to do with feelings, with need, lust, want... and desire.
Those who had been branded by Laz were those who he desired and those who desired him in return. It wasn't just sex, it was a melding of souls.