No it's the anal sex ... you are confusing yourself ... an anus is an anus ... the rectum is pretty much a giant muscle with lots of vascular tissue therefore lots of blood ... and there is lots of friction and no lubrication in anal sex ... coupled with the anus (again for both sexes) is naturally contracted so this constant squeezing adds even more friction and trauma to both parties
thus INCREASING the chance for transmission of blood and HIV virus ... the penis hole is not where the virus enters the blood stream it is broken capillaries and skin cells on the shaft and head ... haven't studied this in a while so correct me if I'm wrong (preferably with sources)
Explain why Man to Woman transmission is so much higher than woman to man?

