In which Korra and Asami are already together, but know one else is aware.
Discovered.
Unlike his brother, Bolin was never a really judgemental person. This had always come in handy. It helped him get along with people and make friends in nearly every circle.
But like all little brothers, Bolin looked up to Mako in at least one respect, and the one Bolin chose was to try and be a protector.
But, Bolin didn't really have anyone to protect. All his close friends could take care of themselves. So when he heard an odd strangling noise one day while walking around what he thought was a deserted Air Temple Island, he of course, rushed to help.
He searched the entire island, finally coming to the Flying Bison stables after hearing another noise come from there.
He opened the door and peeked through it, ready to earthbend at any time, and what he saw nearly made him earthbend himself in the face.
Laying in the softer pile of hay were Korra and Asami, both half-naked and thoroughly enjoying themselves. Asami let out another strangled moan, and Korra playfully told her to keep quiet.
Bolin let out a squeak, and both of the girls jumped and quickly tried to cover themselves.
"Uh, we were just-" Asami true to explain, but Bolin cut her off.
"I don't want to know!" He said, taking deep breaths and trying to calm himself.
"You can't tell anyone, Bolin," Korra said. She didn't sound or look particularly threatening, but he got the message: Tell anyone and I'll bend your ass into a hat with all four elements.
"I-I won't tell! It's you guys's business!"
They both nod, satisfied.
"I think it's cool that you like each other that way anyway. What was the thought process? Mako's been a jerk to both of is so lets just forget him and make out with each other?"
"Bolin," Asami said in a deadly low voice, "Get out."
Bolin's voice raised an octave. "Leaving! I was just leaving!"