There's a fic on Ao3 where Vanessa & Fisk approach Matt for sex (just between Matt & Vanessa, while Fisk watches) after they met him at the art gallery. Matt agrees because he thinks of it as a possibility for reconnoissance on Fisk.

Warning: Though Matt agreed to having sex, it involves him being drugged against his will to keep him docile, if that's not your thing: http://archiveofourown.org/works/3859933/chapters/8620168