No matter what they say, I would feel that it is wrong...I mean, who hasnt seen someone else that they wanted to be with physically?

YET, you do this, and your gf's relationship with her husband may be shattered--they may divorce, and she and he may never speak to you again?

Is it worth taking the chance? I mean, you are an adult, so you can do what you want, I think it is just the idea that we all worry that even one time is too much.

We all know how you feel, really...I mean, I liked girls (when I was a boy) and women (now) that I never could have a chance with myself...

Hope things work out well for you