Rookie Scribe
I think whatever a man a woman do together is straight sex and that includes men receiving anal from their partner. If the man is dreaming of another man penetrating him during anal from a woman, he might have some bi/gay undertones or has fantasies that he might or wouldn't want to live out. That is a grey area in this topic, but I will just go back to my first statement, whatever a man/woman do together and they are attracted to each is plain old straight sex.