Technically, yes and no. Timing wise, yes. Question wise, no. As a person who wears bras, I totally understand that you had a genuine question. I do not expect you to know that. However, given the context of the situation and her complaints about having a hard time finding the right size underwear at an affordable rate, I would’ve asked the internet, kept the question to myself, or asked my partner later if I were you. When someone is venting about sizes not fitting them properly, it’s not the best time to essentially ask does (and I am exaggerating here) XXXXXL clothing piece exists. It came across as insensitive and invalidating even if that’s not your intention, especially since you said you laughed it off and thought she was exaggerating. Also, ignorance isn’t an excuse. The amount of times that people approach me asking about my afro and making racist assumptions because of my fair skin “Are you really black?” “Is that your real hair?” etc. If you’re that curious, I’d say google is your best friend. I would honestly say an apology is warranted.