Straight forward is a bad idea?

Do you think straight forward is a good thing or not? I have a friend which I seen her wearing wrongly so I advice her on the clothing. But seems that she is not happy of it, I mean I tell her about her lingerie that she wears is not suitable for her.

As a plus size myself I know that not all lingerie is suitable for me. It is so obvious that the lingerie she puts on giving her an ugly look. Her bra is too lose and the shape of bra is not suitable for her. I am not peeing on her but her clothing has betrayed her. What would you do is if you see your friend wearing the bra that almost touch her belly? Are you going to keep quiet about it?

I know some people not realize them until you mention it. Maybe you can tell me how are you going to tell her about it.