Zach certainly didn't know what portion of people slept around. It wasn't exactly approved of by society in general. His father was a prime exception to that matter, having been encouraging Zach to do just that since he'd been of age to notice people he might want to sleep with. His father had assumed that those people were of the opposite sex. His father was wrong.
"A decent number do," Zach replied, "It's different with feelings than without feelings. I can't say I know why others do what they do. Some people have told me it's always about making babies, and clearly it's not that. It's...different for different people, it's different with different people." Zach had been horrible at explaining it before, and he didn't suppose he was any better now.
And that reaction...that was about the one he had expected. "We had an unspoken rule before he switched sides," Zach answered, "We didn't talk about anything that didn't relate to sex. I didn't ask him about anything he did, and he didn't ask me about anything either. I know it may be hard to believe, given he's...he was a Death Eater, but he always asked permission, and it was always clear what we were doing. If I asked him to stop, he stopped."
There was a kind of trust there that was different from everything going on in the rest of the world. Yes, Zach had started sleeping with Fletcher before he'd known to think too much of the fact he was a Death Eater. But he didn't regret it or think it that dangerous.
"I don't know...what he's done," Zach replied, "but is it so different from T, from Terrence and Ella?" Zach looked up at Colin, "T's done horrible things. So has Ella. I never talked about it with T, and he never told me. And they both defected and joined your side. No one ever told me to stop being friends with him." And no one seemed to mind that terribly much that they had killed innocent people and would have killed the very people they were allied with not too long ago.