Yep, that's Molly. The moment he mentions that seeing him naked bit, Fjord blushes, then looks annoyed, then looks a little pouty as he lowers the falchion.

"If you'd sleep in your pajamas like a normal person, I wouldn't have seen you that naked that often." He didn't choose to see Molly naked! And Fjord is taking this moment to set the record straight that all of Molly's nudity was 100% Molly's own fault and therefore neither Molly nor anybody else can tease Fjord about it (even though they will totally tease him about it.)

"It's just...somethin' happened back home. When I saw you, I thought 'better safe than sorry.'"