I've had a similar experience with an omegaverse fic recently, too. The only reason I've read it was because I couldn't sleep, was craving fic of my OTP and had read everything decent already. This one had a fair number of kudos and my OTP as a minor pairing. So yeah, I figured I'd give the first two chapters a shot, go "what the hell is this" and erase it from my memories. 20 minutes later, I glanced at the clock and wondered why the hell I was still up at 03:00 in the morning, trying to catch up to the latest chapter of an omegaverse fic.