I am confused by Lord Jornibret's last dance.

for some reason, it seems like the Lord saw a woman he liked and told a man in a bear helm. but then when he danced with the woman, he found out she was the man in bear helm?

it is in song form, and there is obvious sixual innuendo, but I don't get the meaning of dancing with a fair maiden who you never dance with again. are they just using dance as code for six?

any textual insight would be great.