Cosette is a character I would like to see more of (both in the nude and in frequency of appearances
). She initially had the
biggest crush on Marten, who unfortunately was in a relationship with Dora at that time. Marten acted as
matchmaker setting her up with Steve.
Although Steve is Marten's best male friend, they do not hang out much, except when Marten needs advice from a male's perspective (which is not advisable most of the time). Cosette may be partly to blame, as Steve still suspects Cosette has a crush on Marten.
This may very well be true, even if Cosette tries to hide it well.
Still, Marten and Cosette would never cuckold Steve. A breakup might change things, but I do not think Marten and Cosette would get together out of respect for Steve.
Cosette is probably the character that has changed most in appearance throghout the series, even allowing for Jeph's amazing development in drawing style over the years. A particularly hot rendering can be found
here.
EDIT: Added hyperlink to Cosette blushing after a compliment from Marten.