Usually encountered in early teens by females when something sexual happens (ie on television) and they dont quite know how to react.
''That guy is so hot''
''Yeah i Know i just got fanny thuds"
''oh my god did you get fanny thuds too?!"
''Yeah i Know i just got fanny thuds"
''oh my god did you get fanny thuds too?!"
by Hazy2k June 22, 2011