NBA's Doug Christie -- Wife Checks His Testes ... To See If He's Cheating (VIDEO)

Doug Christie has to submit to routine testicle checks ... given by his wife ... who believes she can tell if he's being faithful by checking the size and texture of his man-berries.

Seriously.

Doug's wife, Jackie Christie, appeared on "Raq Rants" -- where the "Basketball Wives LA" star explained why she believes the nut check is legit.

Jackie admits there could be flaws in her system (like cold hands) ... but says follow up squeeze sessions will help with accuracy.