None exists in western culture, matriarchal societies being rare. If one does exist, it may be in the Mosuo language. Although, the Mosuo (or Na) culture tends toward serial monogomy, so even they may not have a word for "male concubine" (a bit of an oxymoron).
groom
Fiancé is the male version. Fiancée is the female version.
In English there are no masculine or feminine forms. English uses gender specific nouns for a male or a female. The word concubine is a gender specific noun for a woman; a word for woman who lives with a man but has lower status than his wife or wives. There is no equivalent noun to apply to a male except perhaps a slave.
A "Dingo" is the male version of a cougar woman!
The male version of Gabrielle is spelt Gabriel
"The Concubine's Children" was created in 1994 by Denise Chong.
Concubine Qi died in -194.
Fragrant Concubine died in 1788.
The Russian Concubine was created in 2007.
The Concubine - novel - was created in 1966.
Fragrant Concubine was born in 1734.
The Magnificent Concubine was created in 1962.