Rivals means constantly bickering, which means being completely at odds.
System: I don't ask for much. Just fall in love with your rival.
Zhou Xi: "..."
Cultivation World
Zhou Xi: Who's my target?
[System: Didn't you just stab him? :)]
School
Zhou Xi: What about this time?
[System: You just got together with his girlfriend.]
Interstellar
Zhou Xi: "..."
[System: I'm not setting you up this time. Your target is your senior.]
Zhou Xi: Really?
[System: Of course. You two have always gotten along great. You've only stabbed each other in the kidneys, that's all. :)]
A top who gets so mad his teeth itch, but can't help secretly gushing over his adorable bottom x a self-reliant bottom who flirts with men like his life depends on it