When one is in the 69 position and the first party discovers that the second party is menstruating, the first party becomes alarmed and jerks, forcing either their phallus and/or pubic mound into the second parties' nose/mouth; thereby causing a nosebleed/bloody lip.
You ever try a Heinz 69? Quite enjoyable once you get past the fact of what is really happening...but a man always knows he's gotta finish.
