Now, of course, if you just can't think straight and your heart starts pounding everytime that person walks by, then you have a problem. Your best bet if to go for a walk and think of a way to convince yourself that he's not your's to have.
BTW, made a little mistake here. I totally forgot that the The Big Bad Wolf wrote the message. So don't think I was infering anything by how I wrote the above paragraph.
One thing I realized a long time ago, is that everything a person does or can do is human.
No matter how you feel, how you act, what you decide to do next has been done before. All by normal people (gay, lesbians, straight) in the same predicament. Even though you may feel ashamed to be in love with someone you are not allowed to be in love with because that person is your friend's partner doesn't make it wrong.