Q. When someone is in a kiddush and he hears someone else making a brocho at the same time he is also saying one, should he answer Amen? If he does is it a hefsek?
A. Horav Shlomo Miller's Shlit'a opinion is that he should not answer amen but rather drink or eat first.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit'a