4060 

Originally a drink with a mix of 40% water and 60% juice. Now used in a situation
when the girl you are fucking is on her period and you ejaculate inside her and a 40/60 mix of blood and sperm is created.

We spilled 4060 all over the bed.

4060 by jhkghfgdfszxdcghvjkj September 13, 2014

40/60

A 40/60 situation is a situation like a 50/50, in which there is an ALMOST equal chance of one thing or the other happening, but the chances are leaning more toward the slightly-more-likely "60" possibility.

Yeah, whether he'll give us a ride or not is kind of a 40/60. It doesn't look real good.

40/60 by Alana July 16, 2006

18/40/60 

Rule that states that a gay male at 18 starts worrying what people think about him, at 40 stops worrying what people think about him, and at 60 realizes no one was thinking about him the whole time.

If I had known about the 18/40/60 Rule at age eighteen, I would have understood the changes I saw in my peers.

18/40/60 by Jack Daniels 2011 November 2, 2011

40/60

When a "straight male" is a slight bit gay, but leans more towards straight. ( 60% straight, 40% gay )

I think he's "40/60".

40/60 by Bubblebiddypop69 June 8, 2022