The male equivalent is the groomsman, also known in British English as the Best Man; in the United States, the role of attending to the groom has diverged from that of escorting guests to their seats, which is undertaken by Ushers, and the two positions are no longer synonymous and are often if not usually filled by different persons.
Notz was the best man to Christopher O'Neill when O'Neill married the Swedish princess Madeleine.