My girlfriend want to play with my ass hole

This may be a bit rude to write the title like this, but just want to share that my girl friend is interested with my butt. I do not understand girls well, how come girls are interested for anal with guys? I understand that if a guy is interested for anal with girls because they have a penis and they enjoy while penetrate into girl's butt, but for girls to play with my butt, it's strange. They can feel high when penetrate my butt with their fingers or some sort of butt plug? But my girl friend always like to oral sex with me and she is wet while doing it. I just wonder if I feel good when she plays with my butt, am I a step near to become gay? At the end of day, I may enjoy when someone penetrate in my butt, it's better that I don't start with anal, once start I may not be able to stop. I just feel gross while imagine myself playing with another guy, that is over my limit, but I have no comment for gay and lesbian. In fact lesbian's porn is one of my all time favourite, who can say no to 2 girls playing in front of you? And having sex with 2 girls at the same time is always a big fantasy for guy, I am so turn on by just thinking of it. There are 2 pairs of breast in front of you, they can make me fainted by just shaking it in front of me. I can be easily turn on by girls, their sexy photo can make me feel high already.