What do you do with a Bai Moo?

This is something I felt strongly during the past few days.

One example form yesterday. When we were having lunch--Fish & Chips, a woman sat next to me said to a student, "You seem to gain some weights since you came to UK." Can you imagine saying this to people when they are having lunch? Well, when I put this in English, it sounds not so bad, but that woman said in Chinese, "You become fat." How is that?

Such a Bai Moo!! I pat on her hand right away and said, "no, you didn't!" to the student. She then said, "Oh, yes. You didn't." Come on... and then she said, "No, actually you seem to lose some weights." Idiot!!! I wanted to yell at her, "Shut your f... up, will you?"

I don't know how come a grown-up can be so Bai Moo. How can I make her understand that she'd better keep her personal opinion to herself instead of shooting it out brainlessly. Even if a person does gain some weights, we don't say it in front of other people during lunch time. Do we do that? How rude she is and I feel shameful sitting next to her. @_@

I hate bai Moo people. They make me feel really bad!!