Kinky thinking

I am in a relationship with a man I have been dating him for a year now and we have sex a good bit but I am horny all the time. every time he leaves for work I have this fantasy about a girl coming over and letting her do naughty naughty things to me. I want a woman to go down on me so bad and I crave to make out with one and get so freaky all night. Does this mean I'm Bisexual. I have never actually done this before and I don't want a three some I just want sex from a girl. I don't know is this is wrong or just a fantasy