Answers:
I'm going to treat this as a serious press...although I can't believe you would ask this.
First of adjectives...AIDS is cause by the HIV virus...not semen!!
You can individual seize the HIV virus by exchanging bodily fluids (such as have unprotected sex...) beside a individual to be precise infected beside the virus...and it doesn't business if you are gay or straight...AIDS is not a "gay" disease! The virus lives within "body fluids"...such as blood - saliva - semen - vaginal secretion...etc...If you don't wear a condom, and hold sex beside an infected character.. you WILL come into contact next to the virus!!
As a concern of reality...more straight individuals within the world own the virus than gay empire!!
So if here is HIV virus surrounded by your semen,,,it doesn't thing if it get into your anus...you've already get it!!
...But I can't see how the semen could procure passed your herald!