Are they two straight stoners who got swept away like college girls experimenting with bi-sexuality? Are they closet cases giving in to their natural urges?

Or are they brothers and the sight of them in a lip-lock is weird in an Angelina Jolie kind of way?

The new Saatchi & Saatchi public service spot on MTV Canada has elicited more questions than answers. It's "dismaying some homos and delighting others," reported Toronto gay newspaper Xtra.

The scene is a modern-day after school special, a "reefer madness" moment set in a parked car. Two dudes in the front pass a bong to their friend in the back. Then the two in the foreground enter into an extended, steamy Brokeback-style kiss. The bleary-eyed buddy in the back seat figuratively rubs his eyes and asks: "Aren't you guys brothers?"

The tag line: "If you're high, just make sure you don't drive."

The 30-second commercial warns that dope impairs judgment. If you're messed up enough to kiss your brother, you shouldn't drive. See it at http://adage.com/vidt?pld=1.