Six doâs, and one donât, for your mother of the groom outfit. By 10 Comments. If, like one of my mother of the groom friends, you bust out crying at the site of beige dresses, youâll be glad to know you probably wonât have to wear one to your sonâs wedding. My mother of the groom outfit search was not without drama. Along the way I found six things to do, and one âdonâtâ, when solving the highly-Googled dilemma of what to wear to your sonâs wedding.