I posted that in reply to someone describing a scene where Brock would be in the kitchen with Aunt May when Peter comes over, and he keeps turning into Venom and making threatening faces and/or mock-licking her behind her back, reverting to Brock whenever she turned around.
In the BtvS episode I mentioned, Lovers' Walk, Spike (who is a mostly-bad vampire and maintained a shaky alliance with Buffy in the past) visits her mother while Buffy is out and befriends her over a cup of hot chocolate and marshmallows. In the meantime, Angel (another vampire, but a mostly-good one, and Buffy's beau) happens to walk by and sees Spike in the kitchen with Joyce, so he rushes to the porch trying to get in but can't, since vamps can only come inside once invited. Joyce is scared of Angel (long story, but the one she really shouldn't be trusting is Spike...) and tries to talk him into leaving, all the while Angel is staring at Spike as he mocks Joyce behind her back and even morphs into vamp face. Very funny scene, and it'd be great to see something similar in Spidey 3.
Hope I cleared that up.