is marques houston and omarion brothers
No, they are not blood related at all. Marques Houston and Omarion consider each other Soul Brothers. For more information on Marques Houston, go here: http://www.ask.com/wiki/Marques_Houston. For more information on Omarion, go here: http://www.ask.com/wiki/Omarion
Yes, Marques Houston and Omarion are brothers, but not biological brothers. Marques simply consider Omarion his musical brother. Learn more about Marques Houston: http://www.imdb.com/name/nm0396867/bio.