[Jack darts him a bit of a look at that last comment.] I think I'll manage, somehow. [Bitingly, as he shakes out his shoulders, and his coat, and draws himself up in at least the semblance of someone who's in control of the situation, even if a large part of him still just wants to grab Spike again and finish what they started.
Truth is, he doesn't want to hurt Ianto. He's just still very new to this true monogamy thing.
He looks at Spike and opens his mouth but can't find anything to say. Everything's either too big or too small; nothing seems to fit. So in the end he just shrugs rather helplessly and inclines his head briefly in parting because hell, this isn't Spike's fault. And he walks away, feeling the most frustrated he's felt in a long time.]