Couldn’t have been legally married in the US if he had a wife in Kenya, could he?
All depends on what kind of marriage in Kenya, legality wise.
Many Muslim male students marry American women while having one or more wives "back in the home country". Which the Americans usually only find out about when they accompany hubby home to find out that they are the "junior wife" and pretty much a slave to the other wives. Muslims LIE, it's what they do. It's a part of their religion.