The second known boyfriend of Adele, deemed "Mr. 21" by fans, is the anonymous ex-boyfriend of Adele who inspired her Grammy-winning album 21. The man has yet to be identified, but many fans, paparazzi, and writers have all tried to uncover who he is. Adele has forgiven him, but has also referred to him poorly on several occasions in the past.
In 2009, when Adele embarked on her first tour, the An Evening with Adele tour, she was introduced to a man ten years older than her (which means he would have been thirty, as she was twenty at the time they started dating). When they started dating, Adele eventually ended up cancelling the remainder of the tour to spend time with him, something that critics responded negatively to, and Adele later regretted. In April of that same year, Adele started work on her follow-up to her debut album 19. 
After weeks of work on the follow-up, only one song emerged from it that Adele was satisfied with - the Jim Abbiss-produced track "Take It All", which would influence the rest of the album's themes eventually. It was written at a difficult point in Adele's relationship with the man, and when she played the song for the man, an argument ensued and the eighteen-month relationship ended. 
According to Adele, the relationship became the "biggest deal in [her] entire life to date", and in addition to being highly compatible, her lover also stimulated her interest in various worldly affairs: "He was older, he was successful in his own right... He got me interested in film and literature and food and wine and traveling and politics and history, and those were things I was never, ever interested in." The relationship ended two years later, when the couple "fell out of love with each other". The ensuing break-up drove her to alcoholism, and left her "angry, bitter, lonely and devastated"; she stated that it may take her "ten years to recover". In an interview with Out, the singer explained that she would have given up her "career, my friendships, my hobbies" just to be with her ex lover:
|“||He was my soul mate. We had everything—on every level we were totally right. We’d finish each other’s sentences, and he could just pick up how I was feeling by the look in my eye, down to a T, and we loved the same things, and hated the same things, and we were brave when the other was brave and weak when the other one was weak...and I think that’s rare when you find the full circle in one person, and I think that’s what I’ll always be looking for in other men. ||”|
She further spoke about him in an interview with Vogue in 2012:
|“||He was great. But it was never going to work. And for ages I was like, As if he deserves any fucking kudos for inspiring my record. But now, after some time, it only seems right that the person who so far has had the biggest impact on me-has now changed my life for fucking ever with this album-deserves a little credit. I can do things that I never dreamed I'd be able to do. If I hadn't met him, I think I'd still be that little girl I was when I was eighteen. And the best thing is, I now know what I want for myself and from someone else. I didn't know what I wanted before. ||”|
Fueled by her heartbreak the singer composed 21 in the aftermath of the separation, and used music as an outlet for her anger and depression. She clarified that the album was not solely about her "bitching about an ex-boyfriend", but that she also wrote songs on which she tried to "be honest about [her] own flaws." 
Following the breakup, Adele went into the studio the very next day and came up with the first single and track from the second album (which would later become titled 21), "Rolling in the Deep" with producer and co-writer Paul Epworth. The song became her most successful song to date. Ryan Tedder of OneRepublic, Fraser T. Smith, Rick Rubin, Greg Wells, and Dan Wilson were the other prominent producers and co-writers who helped to put her emotions into songs. Ryan Tedder's collaborations with Adele (specifically the track "Turning Tables") was an extremely accurate musical interpretation of Adele's relationship with her boyfriend, as Tedder showed up four hours early to the studio and came up with the idea of "Turning Tables" without even realizing it related to her perfectly - she had just come from a heated argument with her ex-boyfriend. The song "Someone Like You", one of her most successful songs to date, was also written about the man after finding out from a very close friend that her ex-lover had become engaged shortly after Adele's relationship with him ended. The song was one of the few tracks written about him in which Adele approached him in a way where she herself was getting down on her knees and pleading for him to come back, the other prominent one on the album being "Don't You Remember", the final track written for the album. 
Below is a list of known songs written about the mysterious "Mr. 21":
- "Take It All"
- "Rolling in the Deep"
- "Set Fire to the Rain"
- "Turning Tables"
- "Someone Like You"
- "I'll Be Waiting"
- "Don't You Remember"
"Rumour Has It" was written about the rumors that Adele's own friends were spreading about her love life and breakup with "Mr. 21", making it indirectly inspired by her relationship with him as well.
Most of these rumored people have been denied to be romantically linked with Adele. Adele herself confirmed she does not know Slinky Sunbeam, one of the first people thought to be "Mr. 21", which eliminates him. She did speak of this man being a boyfriend, which would eliminate her estranged father, another person thought to have inspired the album . Jamie Reynolds and James Corden were both suspected to have been romantically linked to Adele at one time, although Reynolds' publicist denied this, and Corden himself denied ever dating Adele. DJ Ned Biggs was rumored to have dated Adele, and his mother even claimed to remember him dating Adele and spoke of how she was a "lovely girl", even going as far as to admit that she suspected the album might be about him, but a spokesperson for Adele denied this. Mark Ronson refused to comment on this, although given his other romantic relationships, the time simply would not add up to the amount of time Adele dated "Mr. 21". 
In an interview during the An Evening with Adele tour (when she and "Mr. 21" started dating), it was reported that her boyfriend at the time (which, given the length of time they were supposedly together, would make it the same man) was someone named Michael.  Although it was heavily speculated to be singer Mika (whose real first name is Michael), the age difference between Adele and Mika was not as large of an age difference as the age difference between Adele and Michael. It was also confirmed that Mika and Adele are only friends and never dated. 
The majority of speculators believe that Alex Sturrock, her photographer throughout the majority of the An Evening with Adele tour, was "Mr. 21". Sources who have claimed to know Sturrock have revealed to tabloids that they dated throughout the course of the tour, and he ended up serving as the inspiration behind 21.  Others noted that they may have been romantically linked because Adele brought him to the Grammy Awards in 2009 and thanked him when she won the award for Best New Artist. Fans have noted that Sturrock is perhaps the most logical person to be "Mr. 21", although most have chosen not to delve into the subject matter out of respect for Adele.
- ↑ http://abcnews.go.com/blogs/entertainment/2012/02/the-man-who-inspired-adeles-rolling-in-the-deep-revealed/
- ↑ 2.0 2.1 2.2 2.3 http://en.wikipedia.org/wiki/21_(Adele_album)
- ↑ http://theseattlelesbian.com/adele-rolls-in-the-deep-and-inspires-kids-to-come-out-2/
- ↑ http://www.billboard.com/articles/news/506174/adele-covers-vogue-says-shell-never-make-another-breakup-record
- ↑ http://www.dailymail.co.uk/femail/article-2112973/Who-broke-Adeles-heart-star.html
- ↑ http://www.dailymail.co.uk/tvshowbiz/article-1044011/Pacing-pavements-Mika-hits-town-beautiful-big-girl-Adele.html
- ↑ http://www.heatworld.com/Entertainment/Music/2008/08/Mika-and-Adele-dating-What-the/
- ↑ http://www.huffingtonpost.com/2012/04/04/adele-ex-boyfriend-revealed_n_1403224.html
- ↑ http://www.thefrisky.com/2012-04-04/alex-sturrock-photographer-could-be-the-ex-boyfriend-who-inspired-adeles-21/