It's not too much to go on, but here's what I remember clearly from each of the two.
#1- Harry, Pansy, and Blaise became friends, secretly. Harry has a thing for Draco. Revealed at a celebration in ROR Harry gets drunk and he complains about Slytherins with morals.
#2 - HP. HG, DM, PP, BZ?, SF, DT, RW, GW get locked together in a room during a training exercise. the Gryff boys insist Harry tell them a sex story. It turns out to be a real event.
If anyone knows one of these two stories I would be so very grateful. Thanks, in advance!