I'm guessing "Manly Handshake' is a euphemism?

I Always Wiggle My Finger In the Palm and Give a Wink

Link : http://www.collegehumor.com/out2/13145/url/graphjam.memebase.com/2011/08/29/funny-graphs-i-always-wiggle-my-finger-in-the-palm-and-give-a-wink/