However, not everyone agrees that it's funny, and might respond with a sigh.
Connection with Bellsprout:Edit
Bellsprout is the 69th Pokémon, as such when posting with the Pokémon smilies you will get a Bellsprout beside the 69. Long ago it was connected that Bellsprout had such an oddly shaped mouth... The innuendo was made and Bellsprout became the "69" Pokémon.