Honestly Ianto is not sure what to say to all that so he just sort of nods and awkwardly tries to drop the subject. "As long as its more about control I'm fine. I think I'd enjoy that sort of thing." He doesn't want to think about Jack going to someone else to get hurt.
He gives some real though to the question about bondage, taking a slow sip of his tea as he mulls it over. "I think that would be alright." Again, he's seen Jack tied up or in hostage situations more than he likes to think about, but it's a bit different, nothing like seeing him die, and this is a case where he's quite sure he can separate the two. "Sounds like the sort of thing that could get rather interesting."