I found this on this website:
http://www.mahalo.com/how-to-choose-your-wedding-party How should you deal with awkward situations? Follow these creative solutions for when a family member or long-time friend technically belongs in your wedding party but just doesn't fit the in with the style, budget or personality of the wedding. Switching sides: If you don't like your bride's brother, for example, and can't imagine having him tag along at your bachelor party as a groomsman, request that she include him in the bridal party. Small duties: Honor this person with a different role in the wedding ceremony such as ushering or delivering a reading. Leave it to chance: If you just can't afford the extra bridesmaid or groomsmen, tell both that you'd like to include them but that you have to make a random choice. Then, have them flip a coin or pick a number to determine who's in and who's out.
My Grandparents on their wedding day.
bio
Repeat this to your self: My Wedding Party is made of my family and friends and I should treat them as such.