How much HIV risk in condomless cocksucking? The riddle’s as old as the epidemic, and recent developments on both sides of the Atlantic do little to crack it.

Brit health officials issued a summer PSA that skin flute may be riskier than you think -- 3 to 8 percent based on recent studies. Quickly qualifying, they then allowed that “this is likely an overestimate,” adding, with dry Brit wit, “many are reluctant to admit high-risk activities.”

Cut to California, where the prevention priests at UCSF interviewed 176 hummers, 96 percent of whom reported sucking unwrapped salami. At least 50 practiced their art on HIV-enhanced meat; almost 40 of those eschewed rubber and 30 swallowed. So how many new oral-sex infections? Zero.

What to make of these conflicting reports from the fellatio front? As long as the jury is out, the condoms stay off.