"Well, yes, rather," he half-laughed. It wasn't as if he knew where the saddle was!
It also wasn't as if he was going to take this as permission to get her out of her stall, for all that he was, really, quite delighted to be offered the opportunity for more than meet-the-horse-in-cross-ties.
Loki did, eventually, stoop down to fetch the end of the leash out from under his boot, while Sif was gone, and even more-or-less dusted it off so that she wouldn't be stuck holding the incredibly grungy rendition of Jotnar's leash.
(He wasn't sure if she'd notice, but it still didn't do to be ungentlemanly about it.)
"You really are quite lovely," Loki was telling Katie when Sif came back, "and I really do hope that you'll like Jotnar."