Does anything say "I love you" more than hating the same people as your partner?! Whether it's their frustrating colleague at work, or a feud with a cousin, taking on your partner's enemies is a beautifully petty way to express affection. Plus, trash talking someone you're not directly connected to is a truly satisfying past time, you get all of the catharsis and none of the guilt.
On this same note, Serena Williams' husband Alexis Ohanian showed a gorgeously petty expression of solidarity at the U.S Open match against Maria Sharapova.
For context, the two tennis players have been pinned against each other for over a decade. Calling it a feud may be unfair since their rivalry largely consists of Sharapova name calling and body shaming Williams, but it's certainly safe to say the two aren't friends.
One glance at their actual tennis records makes it abundantly clear that Sharapova's unprofessional stance towards Williams is coming from insecurity, since she hasn't beat Williams since 2004.