The word Cuckold comes from the word Cuckoo, a female bird which lays her eggs in other nests. In todays society it is mostly used to describe a relationship where the female partner has multiple sexpartners which is stimulated by the husband (or boyfriend), also known as the cuck. The man gets great satisfaction to see his partner with other (quite often described as superior) partners. Those sexual partners are sometimes referred to as: Bulls (when the sex partner has a big cock) or BBC (short for: Big Black Cock). There are even situations where the husband has no sexual relationship with his partner anymore (or rarely) and the wife gets even impregnated by other men.
In a typically cuckold relationship, the husband gets off by seeing or fantasizing about his wife with another man or even men. It is not unusual that the husband (also referred to as: cuck) gets ‘seconds’ by licking the seemen left by her sexpartners from his wife pussy or body when she returns home or after her sex acts (of which he sometimes is the observer). Sometimes the wife also sends her partner cuckold videos or cuckolding pictures of her having sex with other men.
For some people this seems a bit odd, as the relationship seems to be setup in a very dominant (wife) and submissive (man) role pattern. But it works.