I have always masturbated to thoughts and pictures of male nudity, but I am not homosexual.

I just don't get off well when I think of females. My girlfriend can get me off very easily – but when I masturbate it's much quicker and easier for me to imagine a male rather than a female, even though I do not like guys in that way. I have masturbated with guys, and I have masturbated guys before, and I didn't like it at all. How do I get to where I am more comfortable masturbating while thinking of females? Is it common to think of guys sometimes?

Yes, it is common – more than just about everyone realizes, or will admit. However, most straight males – at least adults – can be sexually aroused by images or thoughts of females. If you get turned on by looking at your girlfriend or a picture of a sexy woman, you probably have no reason to be alarmed. You may develop the ability to successfully fantasize about women as you get older – or maybe your fantasy life will just be different from most straight guys'. However, if you find you aren't physically attracted to images of women but you are to images of men, you don't necessarily need to be concerned, but you should consider the possibility that you're at least bisexual. Admitting this to yourself can be very difficult in our society, but it's all about being true to oneself and being comfortable with who we are. If you're sexually confused and it bothers you, you should seek out help from the many resources devoted to this. The bottom line is not to stress about labeling yourself one way or another, but to learn to live with – and enjoy – the attractions you have. And by the way, you can't force those to change either way.