A biographer is alleging that Adele's bisexual boyfriend left her for a man, The Hollywood Gossip reported.The British songstress' drama and all the juicy details surrounding her breakup have been exposed in a new tell-all book, Adele: The Biography, by Marc Shapiro.

Shapiro is claiming that Adele's boyfriend at the time broke up with her on her 18th birthday, and that was the relationship that inspired her award-winning album.

One thing we know is that it was a first love gone terribly bad, Shapiro writes. Adele had professed her love and he did the same. She had known he was bisexual but, in the rush of romance, felt they could make it work.

The biography claims, Four hours after laying their emotional cards on the table, the boy ran off with one of Adele's gay friends!

Adele was still with the same person as her debut album was getting recognized, and she admitted to canceling appearances so she could spend more time with him.

I was drinking far too much and that was kind of the basis of my relationship with this boy, she explained to Nylon magazine in a 2009 interview. I couldn't bear to be without him, so I was like, 'Well, OK, I'll just cancel my stuff then. ... I can't believe I did that. ... It seems so ungrateful.

Shapiro also asserts that Adele had a drinking problem while on her first tour, according to The Hollywood Gossip.

It's not surprising that Adele was quick to pick up the bottle. What could be worse for a woman than her boyfriend breaking up with her --- maybe when he dumps her for another man. There's no doubt that Adele has soul, but now it's clear where that heartache and passion stem from. If it's any consolation for Adele, at least she knows it's not something that she did.

Check out the video from her performance at the Grammys to hear her sing her heart out: