In a recent episode of the CBS show "Bull" staring Michael Weatherly as the lead character "Dr Bull", the "Episode Details" are something like this (slight variations depending on source):
Episode title: "Separate Together"
Staring: Michael Weatherly, Freddy Rodríguez, Geneva Carr ...
Air date: 01/14/2019
Season 3, Episode 11.
Bull and his romantic rival, Diana Lindsay, join forces to create two defense teams when Diana's niece and her husband are charged with armed robbery; Bull's reunion with Diana is strained by his new post-heart attack regimen.
The use of "his romantic rival" here seems totally wrong to me.
Bull owns a trial consulting firm, and the character Diana Lindsay, is a defense attorney, I gather a rather highly paid defense attorney, and I think she could probably also be described as a "fixer" of sorts (but not the "Ray Donovan" type of fixer). They are not "rivals" to each other in a business sense.
Bull and Diana are on-again, off-again lovers. Neither of them has an alternate love interest (to my knowledge).
So why is "she", his "romantic rival"? It seems like his "romantic rival" in relation to her, would be her husband, or perhaps her long time boyfriend, lover, or partner.
Am I correct to say that "romantic rival" used here is a misuse?