The Lords wife, what`s up with her?

SO...we all see how the Lord Bertilak's wife acts around Gawain: she`s got an idea in her head and it`s like she`s set on a mission. I guess I`m suspicious of what she really wants. Does she really just want to "hang out" with Gawain for the clout since he`s a knight on the round table...or is there something else going on between her and her husband? I think it says a lot about the commitment of a married couple during this time. I think men had so much power it`s almost like the lord`s wife is just a tool to him that he can use when he pleases (or leave alone with a stranger in the castle all day). What do you think her motive is when she goes into the knights chamber? Purely sexual maybe...or something deeper?