Ianto grins at the sound, not about to tell Jack to keep quiet. In fact right now he is really, really hoping every single person on the other side of that door can hear him. He wants everyone Jack kissed tonight to know what is happening in here, especially after the way he spent the evening awkwardly explaining their relationship over and over again.
He leaves the hand holding the remote wrapped around Jack, supporting him while the other finally reaches down to his clearly neglected cock and begins to stroke.