just because he slept with Faye a few times means he is in a ball an chain situation.
Er, wargrafix, weren't you paying attention to the last panel? While I agree that there's a case to be made about Faye bringing any hurt she feels on herself by fence-straddling, it's pretty clear
Sven must think he's in a commitment of some sort. Otherwise, why the worry? In fact, why the 'it's only…' comments all the way through? And if you
think (as opposed to
saying, sometimes also known as lying) you're committed, you pretty much are, yes?
As for simply fearing trouble, Sven seems mostly to only do this
after he's had his fun. We've seen this several times now. But worrying about it beforehand is new.
What would be really interesting: Faye finds out, then Sven goes into the whole Swiffer commercial* thing about it while Dora, observing her brother contrite, goes into shock. It seems completely out of character, but then it also seems to me to be out of character for Sven to give a wet slap about the next minute, relationship-wise, much less the next day. Particularly mid-coitus.
*I always thought whoever wrote "Baby Come Back" (vapid lyrics, limp melody, lame guitar lead) ought to be made to eat two thousand copies of it ('twas back in the days of vinyl). But the mariachi band actually makes it sound not half-bad.