My Mother Is Getting Remarried To My Future Step Dad

My mom is getting married to the man that she has been with for 13 years. I consider him my dad since i never had one and he has been ther since i am 11 yrs old. A friend of mine has a beautiful voice and as a gift to them i am having her sing at their wedding. The problem is that every step dad or father wedding songs always comes back to me being the bride rather then him being the groom. I have a song for my mom that was easy but i need help on this one if anyone has a suggestion. Thank you