Fetishistic Sexual Cuckoldry
Though many attribute the antlers of deer as being simplistically connected to general 'Horniness' (i.e. how 'Horny' someone is), those horns (like the ones illustrated above) were in fact the main symbolism to be found in Classical Cuckolding (as is CLEARLY shown below).
The above satirical painting was done at around 1815 in France. Now part of the Public Domain.
(The painting has been cropped herein for appropriate focus upon the point of interest.)
The main principles within Classical Cuckoldry, the unashamed adulterous wife and the inherently humiliated husband, have remained intact over the centuries; continuing as the centerpieces of today's Fetishistic Cuckolding. Though it may have been subtly symbolized or carefully implied in the old 'Horny' days, modern day Cuckolding's common inclusion of Coerced Bisexual activities ("Forced-Bi") takes things to a further degree (to a different level entirely in some cases).
Originally, the humiliation put upon the Cuckold (Cuck / Cuckee) was chiefly done by the sexually neighborly wife; the Cuckold's Adulterous Wife was the degrading causation. (Although, it was often shown early on that Humiliation received by the Cuckold was known to others, but not to him; being more of a hidden affair behind the naive husband's back.) Yet today we often see the majority of the humiliation (or the harshest levels of degradation) as coming from the lover; the male stud that pleases the Cuckolddress is also he who pounds the inadequate spouse's spirit (Ego) into fine dust.
Here's an interesting little piece of trivia for you (no pun intended):
The so-called "Sign of the Horns", you know, like that shown below:
Although the hand sign is commonly associated with the horns of the Devil, and was involved in the ridding of demons in some forms of Buddhism, it was (and is) also considered to be an offensive (degrading) gesture. In South-Western Europe & in Latin America, it is used as a Mockery towards a Cuckolded husband (in order to bring further humiliation onto him), reminding the Cuckold of the horns upon his head (symbolically speaking).