Final answer:
Annoying couple habits include excessive public displays of affection, arguing in public, preoccupation with smartphones, and overly lovey-dovey behavior, all of which can cause discomfort to bystanders.
Step-by-step explanation:
When considering what some annoying habits of other couples that irritate people the most, personal opinions can vary greatly. Public displays of affection can often make others uncomfortable, especially when they are excessive. Excessive arguing in public can also be bothersome as it can create an unpleasant atmosphere for those around the couple.
Moreover, when couples are engrossed in their smartphones instead of engaging with each other or those around them, it can be perceived as rude or inconsiderate. Finally, overly lovey-dovey behavior such as constant pet names or speaking in baby talk can irritate some individuals who may view such actions as insincere or distracting in certain settings.