To my knowledge, "cuckold" is an archaic term for a man or woman who's partner cheated on them. To date, it is used as internet slang for a political insult and (most commonly) to describe an individual who "gets off" watching their partner have sex with another.

The tag "cuckold" or "cuckolding" seems to imply the "cheating" tag, though it's to my knowledge that the two do not go hand in hand.

On /post/show/1062462 you can see one character having sex with another in front of what is implied to be his partner; along with the usual "he's so much bigger" taunt that generally goes along with the cuckolding fetish. It looks very consensual on all parties (the boyfriend isn't mad, his boyfriend's playfully mocking him about it, etc.), yet tagging it as "cuckolding" immediately implied the cheating tag.

I have no idea if this has been discussed before and don't have anything more to say. But it's to my knowledge that there can be discussed and agreed upon cuckolding. I don't personally think it's wise, but it seems rude to imply that consensual swinging is infidelity; and outdated to assume the majority of people use "cuckolding" to describe adultery.