Explain SMBC — the wiki for Saturday Morning Breakfast Cereal

The Joke

A banner reads: "Relationship Tip: The quickest way to get out of sex is to describe it." Below, a shirtless man says to a woman: "Time to fill the old skin balloon up with blood."

The Humor

The comic plays on the idea that sex, while desirable in practice, sounds deeply unpleasant when described in clinical or overly literal biological terms. An erection — a normal part of sexual arousal — becomes grotesque when described as "filling the old skin balloon up with blood." The humor lies in the contrast between the romantic or passionate framing that typically accompanies intimacy and the visceral, deflating reality of what is actually happening physiologically. The "relationship tip" format adds to the comedy by presenting this as genuinely useful advice, as if describing bodily functions in unsexy medical terms is a reliable strategy.