Part of what you are seeing is the angle of the photo. While there is some swelling under the female, the bulges on the male are enormous. Gram for gram, C. africana males must have some of the largest hemipenes in all of Squamata. The size of the reproductive organs leads me to believe there is intense postcopulatory competition amongst males to fertilize eggs. I suspect males defend small territories, with females moving freely between them. In this system, producing as many sperm as possible is the only way to maximize reproductive success.
