It could be said that Jack's ideas of making up for it did aid in productivity -- just not any sort of productivity that would be condusive to the daily workings at Torchwood. Productivity in the way of making Ianto's head explode and getting his lover to lose all manner of control, perhaps -- but nothing that would actually help Torchwood in general (unless one considered making Jack 'relax' was a good thing for the masses).
No, neither of them were weak-willed -- they simply were two beings that knew when enough was enough and that a few hours on the couch was enough of a punishment for either of them. Granted, it also implied just what Jack felt for Ianto, words that Jack still had issue saying after all this time. The truth of the matter was that Jack couldn't resist Ianto. When that growly accent was turned on him, Jack mindlessly would agree to just about anything.
To be frank, Jack didn't want Ianto to regain any control. He wanted his lover completely undone, wanted to push him to that delicious peak and tumble over the side with him. It didn't matter that these were the archives or that the rest of the Hub knew exactly what was going on in the basement, Jack wanted this and wanted to drive Ianto to the point of madness. The broken words coming from above, half in English and half in Welsh told Jack he was doing his job exquisitely.
It came down to the decision if Jack wanted to get Ianto off completely or leave him at the precipice. Both were exceedingly tempting. Jack finally pulled his head back, tongue flicking across the slit once more. He knew full well how close Ianto had to be, and yet he left him at the edge.
"I do hope you brought slick down with you," Jack said, hands running along Ianto's bare thighs. "Otherwise, we'll be doing this the 'old fashioned' way." Impishly, Jack ran his tongue over his upper lip and watched Ianto's reaction.