The only two I can remember offhand is Ollie implying something untoward about Hal & Power Girl (and Huntress) in James Robinson's execrable Cry for Justice, and, then, Guy mentioning something about them again during Johns's run (I think it was during the War of the Green Lanterns arc).
That said, Gail Simone, who was writing Huntress at the time in Birds of Prey, took issue with Robinson's idea that Hal had a threeway with Power Girl & Huntress and explained it away as a drinking contest that Hal lost.
Either way, if you factor in Waid's icky writing of the underage Supergirl fawning over Hal in Brave & Bold, it makes sense that
something went on between Hal & Power Girl (who is essentially an adult Supergirl). At the very least, Hal's buddies are under the impression that Hal & Power Girl got together at some point, and Hal didn't deny it with either Ollie or Guy.
Given Hal's long established qualities of being fearless
and honest (even if it gets him into trouble), he doesn't strike me as the kind of guy who'd go around pretending he'd slept with women he hadn't.
As for Tasmanian Devil digging Hal? Makes perfect sense. Hal's a hunk