God, that's different. Interesting and fantastic but still different. He leans in, starting to really enjoy himself as he lets his hands begin to drift across Jack's body. He realizes abruptly that they haven't had sex since that time in the couch with the coat. Between Spike being resources and shooting Jack, not to mention their fight they simply haven't. And suddenly as good as this feels he suddenly realizes he doesn't want this. As good as it feels all he wants is to sit down and have a real conversation with the Jack he knows and abruptly misses. He wants to fix things, not have a fling with a fling with a stranger.
Slowly, reluctantly, he untangles himself from Jack, breathing heavily, arms still draped losely around him. "Maybe you should go explore the dome. You must be curious about it."