"Oh, he totally outclasses me, but I cheated not actually knowing how to use a sabre -- I will never get why you didn't ask someone who could use the same weapon, I'd have just let you use the ring," Sif added, tossed out at Loki.
"But maybe that explains -- well, I guess it wouldn't. Since I'm not used to beating people who outclass me, anyway. Lunch?"
Maybe she's just not used to being outclassed by Loki.