https://www.urbandictionary.com/define.php?term=cuck.&page=14cuck
"Cuck" a weak, feckless, spineless, and decidedly pathetic specimen of manliness. It is a dirative of the term "Cuckold", which in turn comes from the now extinct Cuckoo Bird (known for laying its eggs in another bird's nest; kind of like how a cuckolded man lets another man screw his woman).
cuck
A man who lets his wife get rammed by other men. He may watch, or not, but he knows. This may result from:
He genuinely cares, but she is the toxic piece of s*** who gets off testing her mans boundaries. The guy did not push back enough, because he cared, and wanted to give her what she said she wanted. Now, she has managed to push her boundaries all the way to another mans ball sack.
He seeks approval, and the hoe knows it, so she withholds it. Treating him worse and worse, getting off on his humiliation like a sadist. Now, she's on another mans bull sack.
Will Smith is such a cuck! His wife gets smashed by other guys, but he's too much of a cuck to leave that trash, so instead he takes out all these unresolved emotions by suckering Chris Rock! What a cuck! I hope he finds someone who actually supports him and doesn't treat him like s***!