Girthmaxxing is the act of squeezing one's flesh in the penis into the sides of said penis making the sides of the penis more bulky and girthier in appearance. It's one of the 2 steps in penis bending the other being jelqing which increases it's length whilst this increases it's width.
Jeremy: wanna achieve goonvana and girthmaxx
Sara: i can't im still on jelqing
Girthmaxxing is the act of squeezing one's flesh in the penis into the sides of said penis thus making it's appearance more wider and girthier. This is one of the steps of achieving goonvana and is one of the 2 acts of penis bending, the other being jelqing.
Jeremy: Hey you wanna achieve goonvana and girthmaxx with me??
Sara: I don't have a cock