He doesn't know, but judging from that look he's giving, he can't say that he isn't enjoying it.

"Is that what you think, Isaac?" And while he speaks, one of his hands has reached back to tangle in Isaac's hair again; he tugs sharply back on the ponytail, once, hard enough to ensure that he has his attention, but not enough to really cause too much lasting sting - he's noticed that Isaac tends to like that, for some strange reason, and he's not going to argue it while he's in a position to use it.