He wasn't going to bother explaining it. There was no way he could understand that Mohinder was passionate in all areas, and that included mourning and avenging his father. Let Luke find that one out on his own.

The statement about him being 'neutered' made him laugh. If it had been the early stages of his reform, he might've been irked by it, but he'd been happy for too long by now. It was clearly not a state that Luke was familiar with. "Wow, you really don't have any use for emotions at all, do ya, kiddo? Maybe you're not even capable of understanding. In that case, I can only feel bad for you."

He did let go of his hold then, entirely. If Luke fell, then whatever. "You want some dry clothes?"