1) SpongeBob SquarePants but lacking the SquarePants.

2) Someone who refrains from wearing underwear under their outer clothing (i.e. to go 'commando', 'freeballing' - in the case of men not wearing underwear, and 'freebuffing' - in the case of women) to covertly create a frisson of sexual excitement or amusement amongst friends, sexual partners, future sexual partners, etc.

to tell someone to calm down and relax.