Best friends put each other's rectal thermometers in their mouths. Period.
This is what is called a non sequitur. It is also called 'random comedy' and this joke in particular is in reference to a lyric from a Beck song. JOKE EXPLAINED.
Buffalo Bite Football pizza is ready for game time, and that game is called Get In My Mouth.
Bagel heads are big in Asia. That's not a joke, that's just what this body mod is called.