The act of carrying out gay sex. Comes from Brokeback Mountain where the main characters use 'fishing' as their excuse to engage in sexual activities without their wives' consent.
Peter: Wanna go fishing tomorrow?
Tony: You bet, at the motel?
Wife: Have fun guys!
In the summer, putting your index finger up a girls shorts into her vag canal where it's warm, sticky and wet then fishing around for as long as you want.
A false excuse for hiding in your bathroom to pleasure your genitalia. Many people say "I'm going fishing" when trying to hide the fact that they are really going to delve into their lotion stash and being a master debater for hours on end. When you ask how fishing was, his eyes will get wide and reply "don't worry about it".