Not necessarily. O is probably a bisexual.
I heard this rumor about a year ago. A black female writer had floated the idea in a piece about O's connection with Frank Marshall Davis, unfortunately I have neither a name nor a link to the piece.
It's known as "DL" or Obama is "on the down low", a homosexual or bisexual black man who has a wife and kids as a cover. A movie was made about the subject "Cover, 2007". Odd it was released just before Obama hit the scene.