Q. If one is offered something that is cholov stam, and he is not interested in explaining that he cannot eat it, or getting into an argument with someone who relies on Rav Moshe's so-called heter*, may he lie and claim to be lactose intolerant? Is this considered opening one's mouth to the Satan?
*I say so-called because even Rav Moshe holds that it is better to eat only cholov yisroel, and he personally was stringent for himself, so the heter is clearly not 100% l'chatchila.
A. Horav Shlomo Miller’s Shlit”a opinion is that he can answer in general terms; he does not want to partake in the offered food, as he is sensitive and it may harm him.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a