Is it selfish that my sister is asking my husband to shave his beard off for her wedding?

I don't understand whatsoever, my sister is marrying my husbands best friend of 20 years and she has asked that he be clean shaved for their wedding. His beard is not unruly or terribly long, it's just a little bit of hair and I personally think it looks very nice. I think this is a very selfish request. My husband is quite offended because he feels that he was asked by his best friend to be in the wedding for their friendship not for his looks. There are other guys in the wedding who have facial hair and I'm pretty sure she's asked them all but one (he's had a goatee for years) to be clean shaved? I feel like this would be like her asking her bridesmaids to lose weight or dye their hair..