A clueless, bad, irresponsible, oblivious, or idiotic driver. Someone who does something on the roads to piss you the fuck off. People who hold up traffic for miles and seem to not have a clue of what is going on behind them.
When an unfaithful partner has sex and either the man pulls out or takes his condom off in bed the woman then rolls over, typically in her sleep, into said wetspot getting pregnant. The child is then called a cuckstain for life.
He said he is smarter than me he's such a cuckstain.