"Loki remembers the first time he competed against Thor in the Olympics. He wishes he didn't, but it's burned into his mind, probably never to be forgotten. He skated with Sif at the time, but they fought all the time – about Thor, mostly, because she was still on his side, and Loki ached for someone who would be faithful to him, only him. She called him selfish.He'd thought they could win, win the gold, but halfway into it he'd realized that it wasn't going to happen. It had been like a slap to the face (a Natasha slap, full of sharp painted nails). Loki's jealousy was burning so bright he'd been sure Thor could see it from the inside of the changing rooms, a breathless Jane pressed against him." ( Source