htown1980: Anyway, lets have a giveaway. Assuming there is a sale on Friday, two lucky winners will be able to choose US$10 worth of games. This giveaway will be for the boys.
To enter, please confirm you are a boy and write something (possibly amusing) that you think only a boy would know, so that I can be sure.

Exoanthrope: What if I am actually a girl trapped in boy's body?

phaolo: I'm a boy (man lol), but why separating the GA for male\females? O_o

RWarehall: snip

omega64: Would like to be in but can't think of a way to prove I'm a guy.
Kinda weird that you seperate giveaways like this anyway, but whatever it's your giveaway so you may do as you please. ;)

htown1980: I will help then. Perhaps you could describe the feeling of getting punch/kicked in the downstairs area. No girl would know what that is like...

ZFR: I'm in.

As proof I can explain the offside rule in football (soccer).

EDIT: here is a nice explanation even girls would understand:
http://www.bone.me.uk/offside-rule.php

saith32: I'm in!

I will attempt to prove my manliness by telling random observations in my life.

The amount of tomfoolery a guy will engage in is directly proportional to the amount of bros in the vicinity.

High fives do happen often amongst guys to the point of being a little excessive.

There are guys that pop other guys with towels in the shower room and it is almost always the one no one wants to even associate with.

Boobies really can persuade most of us with ease.

The bro code is a legitimate idea amongst men and is punished if you stray from it in many groups.

When a guy says sorry I didn't have time to clean up when his lady comes over, he totally busted his ass trying to clean and is a waiting praise.

And lastly for every paragraph of woman uses in an explanation, a man uses a sentence when he is explaning.
example:
Girl: Omg so I was at Starbucks the other day, and he was totally checking me out. He was so cute and his eyes were so sexy and I loved his hair. He was dressed really nice but I froze and avoided looking at him until I left. What is wrong with me why do I freak around hunts like that.

Guy: yo man saw this hot chick and she had a banging rack.*Awaits bro five*

saith32: The amount of tomfoolery a guy will engage in is directly proportional to the amount of bros in the vicinity[..]
Boobies really can persuade most of us with ease[..]

phaolo: Boobiess.. *drools*
Uh, I mean.. nice XD

You forgot this:
the amount of competition and bullshit told is equal to something like (amount*distance)^[sexyness] of gals around.