This trope describes the situation where a character with a Secret Identity pretends, in their civilian guise, to be friends with that identity. To put it another way, the character pretends to be friends with him/herself to keep up the illusion that the Secret Identity and the civilian identity are two separate people.
Doing this is usually necessary when the character is dropping a lot of clues. If the local hero spends a lot of time protecting Joe Shmo's family and loved ones, or Joe knows a surprising amount about the local villains, or Joe is always talking about how great the hero is, eventually someone will get suspicious. Short of revealing his secret, the best way for Joe to explain his special treatment and inside knowledge is to simply say: "Well, Captain Order? I know him. We hang out."
This strategy has some risks. One of the main reasons a hero wears a mask is to protect their loved ones. If the character's civilian identity pretends to be one of those loved ones, the hero's enemies will trip over each other trying to get to the civilian. It helps if the character frames the relationship as either casual or strictly professional, and informs everyone that they don't know who the hero is beneath the mask. Even so, there's still a chance they could wind up on the wrong end of Bruce Wayne Held Hostage or I Have Your Wife.
See also But He Sounds Handsome, Loves My Alter Ego, Charlie Brown from Outta Town. Contrast Actually, I Am Him, where the character pulling the trick has no Secret Identity to speak of, and can only fool strangers who don't recognize them. If you see something similar to this trope in Real Life, it's probably Alter-Ego Acting (type 1).
- Played for laughs in The LEGO Batman Movie, where Batman claims to be Bruce Wayne's "roommate" so that he can have an excuse for Bruce's (his) adopted son Dick Grayson finding the Batcave under Wayne Mansion. Taken to its logical extreme when he claims that he and Bruce have joint custody over Dick so that he can take Dick on a mission to the Fortress of Solitude. note
- The Mask: Stanley Ipkiss tells Tina that he's a friend of The Mask, and agrees to arrange for her to meet him.
- The Rocketeer: Cliff Secord attempts to tell Patsy that the Rocketeer would help him rescue Jenny as FBI agents suddenly arrive and arrest Cliff.
- In Spider-Man: Homecoming, Ned accidentally lets spill that Peter and Spider-Man are friends in an effort to make Peter look good in front of a girl. An embarrassed Peter tries playing it off by "clarifying" he just knows him from his internship with Stark Industries. Nobody really buys it except for said girl, and even then, it's more likely that she already liked Peter and was using the Spider-Man angle to give herself an excuse to invite Peter to her party.
- In the Sam Raimi Spider-Man Trilogy, Peter Parker sometimes describes himself as Spider-Man's friend and unofficial photographer.
- In The Adventures of Superman Clark Kent is a good friend of Superman's; if anybody needs to get a message to Supes just contact CK at the Daily Planet and he'll be sure to pass it along.
- Superman loves the idea of Identity Impersonator in general, which usually implies at least an acquaintance.
- On the November 13, 2008 episode of The Colbert Report, Stephen Colbert tells the audience he has a "close personal relationship" with Superman, then implies that he is Superman.
Stephen Colbert: ...though we've never been seen together. Hmmm... (curls hair over forehead, takes off glasses)...I wonder why.
- Daredevil (2015): Obviously Matt Murdock has to do this with his secondary identity of Daredevil. This results in very awkward conversations, like in the season 1 finale when Matt and Foggy are talking to Brett Mahoney about information Matt disclosed to Brett as Daredevil.
- Clark Kent uses this trope (as usual) in Lois & Clark. One episode in particular had some reporters find Superman's uniforms in Clark's closet, so Superman appeared alongside Clark (Martha took up holograms as a hobby in the episode) and explained he simply needs to keep them somewhere.
- Supergirl (2015): Similarly to Lois and Clark, Kara uses this, sometimes using one identity to pass along "messages" from the other. Lena is one of Kara's only friends who doesn't know the truth, so this trope comes up most often around her. Kara also gets in trouble for trying to write an article with Supergirl as her only source, which is on shaky ground when it comes to journalistic integrity.
- Wonder Woman: Wonder Woman often talked about Diana Prince, calling Diana Steve Trevor's "capable assistant" at one time and in "The Man Who Wouldn't Tell", Wonder Woman finishes a transformation by calling out "Diana! Run!" to get people to think that Wonder Woman is arriving on the scene while Diana Prince is fleeing.
- On Mahou MUSH, Mamoru Chiba (aka Tuxedo Kamen) anonymously runs one of Tumblr's most popular and prolific unofficial fan/info blogs on Sailor Moon and her allies, featuring pictures, 'sighting' stories, commentaries, and egregious shipping. He doesn't claim to know Sailor Moon or Tuxedo Kamen, merely to be a fan, but the general concept still applies.
- Ben 10:
- After saving Kevin as XLR8, Ben tells him that he and his alien alter-ego are tight.
- In "Ready to Rumble", after becoming a wrestler as Four Arms, Ben claims to be his manager in order to get the prize money as himself. Later in the episode, after Gatorboy and Porcupine see him as Ditto, Ben also pretends this is the case.
Gatorboy: Your wrestlers are amazing! How many guys do you manage?
Ben: Ten... and counting.
- Prince Adam in He-Man and the Masters of the Universe (1983) claimed to know his alter-ego, He-Man. He would often pretend to cowardly flee from a dangerous situation to tell He-Man that everyone else needed help, when he was really just going for a secluded place to transform.
- Princess Adora also did this with her alter ego, She-Ra: Princess of Power.
- VeggieTales: In "Larry-Boy and the Rumor Weed", the mayor of Bumblyburg calls Larry to ask him to send his pal Larry-Boy after the titular Weed.
- When The Treasure of the Sierra Madre was adapted into a film, author B. Traven sent a friend of his, Hal Croves, to be a technical adviser on the film. Reportedly, "Croves" was actually Traven himself.
- Daniel Handler claims to be the public representative for Lemony Snicket, the author of the A Series of Unfortunate Events. In truth, Handler wrote the series, and Snicket is a pen name (and an actual character within the series).