Q. Do a bride and groom to be married on the night after Assara Beteves have to fast until the chupa, as is usually done, which may be hours after the fast has finished for all others?
A. Poskim disagree. Some maintain that since the main reason for the fast of the newlyweds is to avoid inebriation at the time of the chupa, that may render questionable this most important act. therefore, the fast should indeed continue until the beginning of the chupa (Aruch Hashulchan E.H. 61: 21). Others maintain that the grounds for fasting is that it is a Yom Kippur day for them since all sins are forgiven in that day, and it would suffice until the end of the day. (Pischei Teshuva E.H. 61: 9, quoting Chochmas Odom 115: 2 and others).
Horav Shlomo Miller’s Shlit’a opinion is to be lenient,
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a