The US soul singer shocked housemates - and viewers - when he asked to leave the Channel 5 show over the weekend, just hours after telling the housemates he was going to try to keep his cool and get through the process.
Alexander gave his first post-exit interview to Emma Willis tonight, saying: "The stress became unbearable. I did it for myself and for my housemates."
The American star made no secret of the fact he didn't like fellow housemate Perez Hilton. The two had clashed before Alexander's exit, resulting in Alexander receiving a formal warning from Big Brother for homophobic language.
He apologised and said he hadn't meant to offend anyone.
Alexander told Emma that he chose to leave after realising "the Perez problem" wouldn't go away, and he didn't want the tension between himself and Perez to affect the experience for the other housemates.
He said it was hard to find alone time in the house and stay away from the tension.
"Perez is gonna be Perez and do what he gonna do," said Alexander, warning other housemates to "keep your guard up" around the US gossip blogger or risk being "sucked into his drama."
Alexander accused Perez of "taunting" the housemates, adding that he thinks Perez's game plan is to "cut the house down" so he has more chance of winning.
The singer said despite the Perez issue, he had "many good times" in the house and would leave with good memories. He said he was "very touched" to see how unhappy the housemates where at him leaving, but reminded them to remember it's just a gameshow.
As for whether he has any regrets, he said: "I've had my moments, for the most part it was a great experience... I'm grateful to Big Brother for giving me the opportunity to be part of something like this."
However, when asked if he'd recommend Big Brother to pals, cheeky Alex replied: "Maybe to some enemies!"
Alexander was the third celebrity to leave this series of CBB without a public vote: former Baywatch star Jeremy Jackson was kicked out for unacceptable behaviour, while Ken Morley was booted off for offensive language.
So far, model Chloe Goodman is the only star to be evicted by public vote.
As a result of Alexander's departure, the Tuesday night live eviction has been cancelled - although the housemates were unaware of this when nominating yesterday.
Alicia Douvall, Perez, Nadia Sawalha and Katie Hopkins were all nominated but Emma Willis has teased instead of an eviction, we'll see a live twist on Tuesday night. Ooh!
Meanwhile, Perez made it clear yesterday he was ready to go home.
After hearing the results of the first Diary Room nominations, he shouted out: ""Thank you! Send me home! Me, me, me! Public, I would really love to go home!"
CBB stars without make-up!
Copyright: Channel 5