Silly fanny is the grabbing of sensitive areas of the body (bottom, crotch, legs) against the will of the reciever, usually while giggling (high pitched and girly) or pulling a funny face... OR giggling AND pulling a funny face.

However it only really becomes true silly fanny when two people (generally men) are doing this in a public place that will result in embarrassing near by friends.
man Ed and Joe were being so embarrasing playing silly fanny last night in the middle of the pub... it got REALLY gay
by Joveie February 21, 2010
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