Well you didn't think the Clown Prince of Crime was going to be all lovey-dovey, did you? He's not that kind of clown.
The clip above -- from what looks like surreptitiously shot video -- purports to be from the set of David Ayers' upcoming Suicide Squad movie, which assembles a bunch of DC Comics villains for a big black ops mission . There's not real audio but you can see Margot Robbie's Harley Quinn and Jared Leto's Joker talking, kissing and, um, not-kissing. The slap in the video seems to hint that the dysfunctional nature of these two villains' romance will be intact in the movie.
Update: The footage has since been pulled offline at the request of Warner Bros.