Lest you saucier Garfield readers think for a moment that Jon is being euphemistic in panel two, there is no double-entendre listing under "bug zapper" in any slang dictionary.
Thankfully, though Jon made it far enough into a date that he could attempt a kiss, there is no ultimate change in the romantic status quo. Jon's situation is so familiar that at this point, we not only need no jokes about his plaid jacket and polka dot tie, but no character need even acknowledge the outfit.
Dental Hijinks: The urban legend of dental equipment picking up radio waves is a little hackneyed even for Garfield: kid's book author Daniel Manus Pinkwater used it in Fat Men from Space, and Lucille Ball used to claim that signals on her fillings helped apprehend Japanese spies in California. It is cool how the radio fillings are just the middle link in an increasingly absurd plot... though as in the best Garfield, the on-page action is a man talking to his cat at the table.
Hawai'iana: In slight cultural faux pas, Jon has mistaken a dance for a type of music. The musical song and chant of the hula is a mele. Garfield, meanwhile, upon hearing that his owner is endowed with this strange power, is inspired to eat. The slight zoom-in for panel 3 is most certainly just to fit longer word balloons into the panel, but is jarring and forces us to consider Garfield's gross overreaction, and his logic which goes: music from teeth -> late night feast.