Ianto's first time being far less of a big thing to Jack, this probably was Jack's most intense experience with Ianto. Certainly it's the most he's ever opened up to Ianto, the most unguarded he's ever been. He didn't dare let himself slip under as far as he would have done with a more experienced top, but even so... It's a big step. A huge one.
He wraps his arms even more securely round Ianto to make up for Ianto letting go, and shudders a bit at the feel of slick fingers pressing against his stretched opening, and again at the determined tugs to the plug. He closes his eyes and concentrates, and finally feels the toy slip out, leaving his ass feeling huge and empty and gaping. He shivers again, and melts back against Ianto again, gasping.