Most cuckold husband love to masturbate, playing with their cocks as they watch their wives have sex with other man in front of them.
This can be such a visual thrill of the cuckold, the hot wife and the bull. The cuckold gets the thrill of watching his wife becoming a slut for another man, watching a big cock in and out of her mouth or pussy. The hot wife loves the attention, enjoying the way her man (boyfriend) is thrusting in and out of her, while maintaining eye contact for seconds with her husband who is urging her to go on. The bull loves dominating the hot wife with his cock, while watching her husband, helplessly masturbating watching the fun.
While some cuckold husbands may masturbate watching their wife fuck in the same room, others would be polite enough to leave the entire bedroom for the wife and her boyfriend to do all the kinky fun, while the husband watches them from the corner, with a stiff cock in his hand.