Hey, OP here. Here are some more details, for those curious: - All FMLs must begin with the word "Today", but this actually happened a couple of years ago. My GF and I are still together. - Yes, it was a full-blown panic attack, and the only one I've ever had in my life. Never having experienced one before, I thought it was something like a heart attack. What got edited out of the FML was that we actaully called paramedics and I ended up in emergency. - We got the handcuffs off and some normal clothes on my GF (I was already fully clothed) before the paramedics arrived, so there was no need for embarrassing explanations. For a minute though, it was a real concern. - I still don't know what exactly the trigger was. Both my GF and I were pretty nervous and weren't really enjoying ourselves. (We should have stopped when it was clear that neither of us really wanted to continue, but we figured we would try anyway.) I think her anxiety contributed to mine, eventually leading to the panic attack. - We *did* try again a few weeks afterward, when we were both much more "in the mood." No panic attack that time, but we pretty much confirmed that neither of us liked being restrained before or during sex. We both had fantasies about this sort of thing, which is what led us to try it in the first place, but reality proved much different than our imaginations. - For those wondering, they were simple police-style handcuffs, not anything specifically made for bondage play.