Well, no point pushing the button yet, not till the toy is fully inside him, and that's going to take a little while yet. Jack likes the fact that Ianto has the remote already, though. It's like a promise, something to look forward to once he's got this monster inside of him. He didn't think of it as a monster when he bought it, but now, feeling it slowly slide in, widening discernably as it goes, he's definitely feeling the size of it. Not that that's a bad thing, just that he's worried it might take a bit longer than he expected and he doesn't want Ianto to get bored. He promised him a show, after all.
"Oh fuck, this thing is big!" he gasps out, pausing for a moment to just try and breathe and give his body a moment to adjust. Speaking, after being silent (or at least, non-verbal) for so long, is a bit of a release too, which is why he's doing it. His eyes lift to Ianto's face again as he gives him a slightly strained grin. "I'm going to be so stretched after this. Your slut, all open and gaping for you."