Since "domestic partner" is a politically correct way to refer to the person you live with (carnal benefits optional), police officers, lawyers, and other people who work with colleagues also get to utter the above Stock Phrase when introducing their professional partners, Not That There's Anything Wrong with That optional.
This trope is Older Than They Think because "partner" has always had that double meaning, and it's a handy way to drop in some Ship Tease or Ho Yay, but expect to see this trope pop up more and more in lieu of (or in conjunction with) She Is Not My Girlfriend.
Compare and will likely overlap with Strictly Professional Relationship.
- Something similar in the English dub of Samurai 7. Kambei calls his war buddy his "old wife", and this is translated as having him refer to the guy as his "mate". So, in English as in Japanese, the other characters are surprised when they meet the guy and find out he isn't a (female) love interest.
- There has been some confusion on the term "partner" in Negima! Magister Negi Magi (between the festival and summer arcs).
- In Detective Conan Shuichi Akai refers to Gin as "the one that got away" (even going so far as calling Gin his koibito, i.e., "lover") so anyone who overheard him talking would think "ex-girlfriend who initiated the breakup" rather than "criminal that slipped through his fingers"; Detective Kaito, when asked about his relationship with Conan/Shinichi by the Suspect of the Week, uses the identical metaphor, since he both anticipates that his Worthy Opponent would always show up to thwart whatever he's doing but also dreads the interference.
- Inverted in American Beauty: when welcoming Colonel Fitts to the neighborhood, Jim Olmeyer introduces Jim Berkeley as "my partner". Colonel Fitts asks them to cut to the chase and proceed with the sales pitch, as he presumes they're business partners, and reacts with disgust when he realizes they mean romantic partner.
- Very common in The Hollows books between Ivy and Rachel; compounded by the fact that with Rachel under Ivy's protection, other vampires assume Ivy must be getting blood and/or sex in return.
- Though they do become an Official Couple later, FBI Special Agents Zane Garrett and Ty Grady have gotten this. After a car accident, an EMT tending to Ty asks Zane if they're partners. He answers yes, not thinking anything of it. It's only when Zane specifically mentions working on a case that she realizes they meant completely different things.
- Often but not always averted on Bones - everyone seems to think Booth and Brennan are a couple but they always say "we're not a couple, [he/she]'s my partner," and the corretee almost always knows what they mean.
- Inverted in an episode of Psych when a man introduced his "partner." Career policeman Lassiter simply did not comprehend that he meant lover and assumed business partner or partner-in-crime.
- Doctor Who: The Doctor is always having to clarify that a "companion" is not sexual (actually, the term is an Ascended Meme, since it wasn't normally used that way in real life until the show did).
- Law & Order: Criminal Intent - When Bobby Goren's brother, Frank, first met Eames, he got the wrong idea, which he then passed along to their mother. Frank eventually recognized the misunderstanding (though he continued to doubt that the relationship was strictly platonic), but their mother (terminally ill in addition to her long-term schizophrenia) never quite figured it out.
- Mike and Carl in Mike & Molly.
- Reba: Van auctions a day of working out with him in a silent auction and the winner of the auction was an effeminate man who wants to understand football better because his "partner" always talks about it. Turns out he's straight and he was talking about his business partner.
- In Scrubs JD refers to his Heterosexual Life Partners Turk as his "partner" (since they're more or less an internal medicine/surgeon team), then hurriedly clarifies "not that type of partner". Later, it's revealed that his patient had the right idea to start with and got the wrong idea from the correction.
- The X-Files Mulder and Scully run into this, too. The fact that they're closer than most married couples likely doesn't help the situation.
- In the pilot of Common Law, Wes and Travis realize in the middle of their therapy session that the rest of the group thinks that Wes and Travis are domestic partners as opposed to police partners. The fact that it was a couples' therapy group probably had something to do with that assumption.
- In The Fresh Prince of Bel-Air episode "Mistaken Identity", Will and Carlton are falsely arrested in connection to a rash of carjackings in the area. When the latest victim comes to the jail to see about his car, he tells the sergeant in charge that the boys weren't responsible and that they're "[his] partner's son and nephew". Before the obvious assumption is made, Uncle Phil clarifies that the man is his legal partner and then berates the cops for ignoring protocol, demanding that they release Will and Carlton immediately.
- The Venture Bros. Return to Spider-Skull Island begins with Dr. Venture admitted to a hospital emergency ward. Brock goes to follow him in but is stopped by a doctor.
Doctor: Sorry, sir, medical personnel only beyond this point.Brock: I'm staying with him; I go where he goes.Doctor: Ohh! You must be his partner, then!Brock: Not really, it's more like I work for him—wait a minute, NO!