Smilin' Dave
A person who behaves with exaggerated phoniness in social situations. Can be a noun, adj. or verb.
"I hate parties because I get sick of having to Smilin' Dave for hours."
"I freaked out and had to leave because I got accosted by five Smilin' Daves trying to get me to take the Scientology test."
"I freaked out and had to leave because I got accosted by five Smilin' Daves trying to get me to take the Scientology test."