red-flag-2
Explanation
This comic plays on the phrase "red flag" in the context of dating. In the first panel, a man at a bar tells a woman, "You know, if I were on top, my hands would be free." This sounds like a sexual innuendo, and the woman asks, "Free to do what?" He replies: "To talk dirty."
The punchline comes in the final panel, which reveals they're at a semaphore fan convention. The woman is now shown holding two red semaphore flags, and a sign reads "Welcome Annual Semaphore Fan Convention." The man's earlier comment — "Mother of God" — shows his awe at her flag-signaling skills.
The joke operates on multiple levels of misdirection. "If I were on top, my hands would be free" initially sounds like a suggestive bedroom comment, but it actually refers to being on top of something (a hill, a platform) where he'd have room to signal. "Talk dirty" sounds sexual but actually means communicating using flag semaphore — literally "talking" with flags that happen to be involved in "dirty" (outdoor, physical) activity. The "red flags" are literal red semaphore flags rather than the dating warning signs the audience expects. The entire comic is constructed as a series of double entendres that all resolve into the innocent world of semaphore enthusiasts.