Thor opened his mouth to make a retort, but Loki beat him to it with his clarification. Which totally ruined the great joke he had about some little woman holding on to Loki's short and curlies. Dammit.
"You're awfully picky," he drawled, "for a man that doesn't swing a mighty hammer like mine. Oughtta be grateful for what you can get, doncha think?"
The tease only worked because there was absolutely no truth behind it. Loki got women just as easily as Thor did, just for different reasons.
"So," he concluded, "you don't want an extra short 'un, 'cause she'll creep you out. You don't want a feisty 'un, 'cause she'll break you. So we need to find you a gentle giantess?" Thor ran a hand over his hair and gave a gusty sigh. "I dunno, Loke. Gentle or not, I think 'un a' 'er kind, you get into it with 'er, things are gonna start moving, and 'un a' 'er knockers might do more damage to you than a handful a' Valkyries."
This time he held the serious expression. It was difficult, but he did it, so it looked like he was genuine in his concern.