Several news companies have run recent articles on penile fractures. ABC News. NY Daily News. Scientific American. Are longer penises more likely to fracture? I'd think so, but I don't have any statistics to prove that. Which is more likely to break during vigorous woman-on-top sex, a a 4 inch penis or an eight incher? If the 4 incher gets 4 inches inside and the woman shifts her body, the penis will move along with her. If an 8 incher gets 4 inches in, and the woman shifts her body, the 4 inches inside will bend one way while the rest of this penis outside her body might not.