Kissing is an integral part of our sexuality as it triggers a cascade of neural messages and chemicals that transmit tactile sensations, sexual excitement, and develops a deep sense of emotional intimacy. When your wife kisses her bull passionately, it actually helps her lower some emotional barriers or feelings of guilt (related to the fear of public slut-shaming or mom's disgrace) and connects the couple on a much deeper level, which is why interracial kissing is so damn hot!
In that sense, a deep kissing scene has obviously great emotional impact for a husband who stares from distance aroused. In most cases it brings excitement and raw jealously although, for some newbies who're not ready to deal with excessive angst and insecurity, a public kissing scene can be equally devastating and embarrassing. Some say, it feels like a punch in a stomach at first, but the moment a husband embraces his new role and accepts that control has irreversibly shifted in his marriage, this is when the delirium & fun starts.
It's not a coincidence that partners who initially set ground rules like the non-kissing rule or non-anal rule are awkwardly the first ones who broke them! Many cuckolds openly admit that French-kissing their wife while she's been anally fucked by her BBC, works like a charm on bringing down their emotional barriers and feelings of guilt (related to sexual inadequacy, beta nature acceptance, etc.).
At the end of a day, what do you reckon it makes a hubby without prior bisexual tendencies, brave enough to get down on his knees, crawl over his freshed-fucked spouse and use his tongue to clean out her cum dripping pussy?