But the rules you set the first time around might be even more important when you revisit a fwb after some time apart. After all, circling back to the same person (even if it's just for casual sex) has to indicate that you care about them, right? At least, that's what many people might think. And starting to care for someone leads you into tricky waters. So what's the deal? Is it always a bad idea to ask an old fwb if they'd be down to start sleeping together again? Are you only allowed to circle back once? Or can you revisit the relationship whenever you want?