On the one hand, it was explicitly understood between us that this was a strictly fwb thing, so any "claims" beyond that were never discussed, even though, as it turned out, they could have been. On the other, we had been friends before, and after the benefits eventually petered out we still remained the regular types of good friends. In a way, we've never not been at least 80% on the same page. So from my perspective it was a more or less smooth sailing and a positive experience while it lasted. You don't really fight with your friends, or at least I don't. And then there was a 3 year break when we hadn't seen each other at all due to moving to different cities. And after we found each other living in the same place again, that's when some underwater weirdness came out. Both in the sense that we could discuss our past experiences afresh, but also because my friend would now get explicitly jealous about my new partners.