Absolutely! Plenty of guests wear black to weddings, whether male or female. Rock your best LBD or black suit and enjoy yourself. Heck, sometimes even brides wear black, such as the black dress Sarah Jessica Parker wore to marry Matthew Broderick in 1997. Most bride and grooms have no problem whatsoever with guests who want to wear black, with some brides even going the opposite route and having bridesmaids who wear white. Wear what makes you feel comfortable and attractive so long as goes with the theme of the wedding. Cheers!