Actually, the risk of infection depends more on whether or not you receive anal. If you are the 'top', or rather if you fuck somebody in the ass rather than take it in the ass, your risks are significantly reduced, regardless of the sex of the person on the bottom.

It is much easier to tear the tissue of the vagina, and certainly the anus, letting the virus penetrate into the blood stream, over tearing the skin of the cock.

Therefore you would not be 'much more lightly' to catch HIV from having sex with women than with gay men, you would be much more lightly to catch HIV from recieving semen in the ass.

PEOPLE WHO ENGAGE IN ANAL SEX, REGARDLESS OF GENDER, ARE THE MOST AT RISK OF CONTRACTING THE DISEASE.

Then people who engage in reckless behavior, are even more in danger...