"They have a great relationship. Garry has always been there for Barry."
So far, there's been no official word from Manilow or his representatives on the subject.
While the longtime partners now both wedding bands, the National Enquirer reports that no paperwork has been filed to formalize the marriage.
Apparently, the star who has millions of female fans around the world, was worried that if they made their union official, word would leak out about his sexuality and that his fans wouldn't approve of him being gay.
But an insider told People that he went ahead and tied the knot with Kief because "he's got his career and personal life in a great place and he really doesn't care what people think."
"He's in love and happy."
According to the National Enquirer, the Could It Be Magic crooner's longtime friend and Palm Springs neighbor Suzanne Somers was the best man at the ceremony and Marc Hulett, who's been Manilow's assistant since the 1980s, oversaw the proceedings after he registered online to become a minister.
The tabloid reports that Kief was once married to a woman with whom he has a daughter but that he and Manilow have been together for more than 30 years.
Brooklyn native Manilow, whose birth name was Barry Alan Pincus, has sold more than 80 million records worldwide making him one of the greatest artists of all time.
He's had a strong of hit singles and multi-platinum albums and in 1978, five of his albums were in the best-seller charts at the same time.
His hits include I Write The Songs, Can't Smile Without You, Even Now, Tryin' To Get The Feeling Again and It's a Miracle.
His songs of love and yearning have garnered him hundreds of million of fans and many awards since his breakthrough hit Mandy in 1974.
He was discovered first by Bette Midler who hired him to accompany her on the piano and serve as her musical director.
A couple of years later he was signed by record producer Clive Davis and his second album Barry Manilow II that featured Mandy, One Voice and This One's For You catapulted him to international fame.
During the 1970s and early 1980s, he enjoyed phenomenal success with sell-out concerts and high-rated TV specials and his song Copacabana was used as the basis for a musical.
His early 80's hits included The Old Songs, I Made It Through The Rain and Read 'Em And Weep.
He has continued to release new albums and has had two hugely successful Las Vegas residencies in the last few years.
He is currently touring the U.S. with his Manilow - One Last Time! show.
The singer and songwriter does a lot of charity work and was one of the first stars to commit to helping the late Elizabeth Taylor when she first began trying to raise awareness of AIDS and raise money for HIV/AIDS research.
- Daily Mail
