an actual sock of any material or color that is used by a guy to shoot hot cum into when jacking off. the sock is placed over the hard dick and is worn during the entire act of jacking off as to collect cum and clean the dick when done.
I gave my boyfriend a cum sock to wear on his dick while I watch him jack off.
literally refering to one who is used to collect cum before being thrown in the corner or discarded in another unrepectical manner...
My ex is a cum sock.