why does my dog fake nice then go full gremlin?

So my dog’s got this act down. He spots another dog, drops low, tail wagging like he's the friendliest thing ever. People smile, dogs come closer—and then boom. Instant barking, lunging, sometimes he even snaps at their ears. 😩 I’m now that person constantly yelling “he’s not actually friendly!!” while trying to drag my little drama king away. No idea why he fakes it so well—like, why even pretend to be social?? Anyone else dealing with a dog who lures others in just to cause a scene? #dogbehavior #naughtyboy #dogownershelp