Dicks out for

Show some respect in name of (...) .

Making a show or statement, usually in protest of something that is seen as unjust.

When teeing off during a game of golf, if a male fails to hit his ball past the ladies tee blocks, he must open his fly and let he penis hang out in full view for the remainder of the hole.

It refers to a pistol with an extended clip that does not fully fit inside the gun. It seems to have been coined by the rapper Young Thug. It became infamous in the aftermath of the death of Harambe the gorilla, due to people tweeting about it, originally intended as a show of force against people disrespecting Harambe. It degenerated into a bad joke when people interpreted it literally as meaning to display their penises to mourn Harambe instead.

used to describe a woman engaging in sexual intercourse with a male.

To become a dick suddenly and for no apparent reason

When you are having sex and the rhythm is just starting to get good, and the dick falls out. You have to put it in again and start the rhythm all over again.
For this reason, the term can also be used when something was great and turned shitty in a minute. Or you thought you had something and it was ripped out of your grasp at the last second!