A mystery ’80s song dubbed ‘Everyone Knows That’ has finally been identified online thanks to its feature in an old porn film.

In 2021, a snippet of the catchy pop track was uploaded to YouTube and shared on the forum WatZatSong in the hopes to identity the track, which also became known as ‘Ulterior Motives’.

Despite sparking its own subreddit community with more than 47K members – while even drawing press attention from publications like The Guardian and Rolling Stone – internet sleuths were unsuccessful in tracking down the elusive song.

The original poster claimed they found the song snippet amongst files in an old DVD backup.

During the years-long search, users eventually narrowed the song down to a series of rights holders from the mid-1980s.

One user, called south_pole_ball, discovered that one listed songwriters called Christopher Booth had created works for porn films.

They then proceeded to watch through his entire body of work until finding ‘Everyone Knows That’ exactly one hour, seven minutes and 31 seconds into 1986’s ‘Angels of Passion’.

Booth himself has since reacted to the discovery, writing on Instagram: “Well today, my mind has officially been blown:) WOW! #ulteriormotives #ekt”.

The full version of the song can only be heard alongside the NSFW sound effects from the movie – or fan-edited versions – prompting new-found listeners to request the original version.

Booth, who is credited on the song along with his brother Philip, has since taken to TikTok to tease: “Shall we release it?”

One moderator of the r/everyoneknowsthat subreddit has reflected on the “rollercoaster ride” of the search as part of the Lostwave community, which identifies and spotlights forgotten music.