"Gossip Girl" is going boy-on-boy.
Ed Westwick's character, Chuck Bass, is filming an episode for the hit show's third season in which the hottie actor locks lips with another man, Entertainment Weekly reported.
Westwick's Bass gets up close and personal with "CSI: NY" actor Neal Bledsoe in the episode, which features Chuck as he attempts to help girlfriend Blair Waldorf out as she begins her career at NYU.
Bledsoe plays an NYU administrator who's choosing a freshman speaker -- and type-A Blair wants the spot so badly she pimps out boyfriend Chuck to Bledsoe's gay character Josh Ellis.
No word on whether Bass would slip Bledsoe the tongue -- but insiders confirmed the lip-lock has juicy repercussions in the series.