A male cat has actual barbs on it - interestingly enough, however, it does not appear to be the barbs that cause the female to cry out. When a male is neutered, they loose the barbs on the penis. Many breeders will castrate a tom and use them as 'teasers' for females they don't want to breed right at that time, but they want to take them out of heat. The castrated toms will mate and cause the girls to cry out, but they don't have barbs on the penis, so that theory doesn't make sense. Please click on the "VIEW FULL IMAGE" to see a picture that may assist. The tiny picture below is distorted and not easy to view.
Please let me know if I can assist further.