As many bi people will tell you, one is rarely ever attracted both cocks and cunts equally. Sometimes this means that you spend all of your life being attracted to one and flirting with the other on occasion, sometimes it means that you'll take either gladly but have a slight preference for one. Often preference changes.
Myself? Well, I tend to hang out around the 'either's good, both is better' part of the spectrum, with a slight preference for cunts. Most of my long term relationships have generally been with guys, simply by virtue of the fact that there are far more straight/bi guys in this world than lesbian/bi girls so there is far more chance of me finding a compatible mate in the former group. But when it comes to fucking other people I'm all about the girls. Oh, you have a penis? That's nice dear, hope it makes you happy. There's a slim to none chance that I'm going to like it better than Mr O's fabulous specimen, so don't waste my time. You have a cunt? Well why the fuck are your clothes still on? Sit on my face now! That is, until this week. Suddenly I am cock crazy and can't get enough of it.
Why this sudden change? You could say it was part of the natural fluctuation that one experiences. You could say that it was because I've just come out of a relationship with a very selfish cunt that didn't like fucking me nearly as much as I liked fucking it (or was just too lazy to be bothered returning the favour?). Or you could say that it was because last Monday I experienced my first ever DP.