Dear Prudence: My 20-year-old son, "Ted," has a 19-year-old girlfriend, "Dahlia." Dahlia is very well-endowed and rarely wears a bra. However, she does wear low-cut clothing and often looks like she's about to fall out.

Here's my problem: She's going on vacation with us in a week. I don't want to seem prudish but I do want to get through to her that this type of dress isn't appropriate for the places we'll be going and the people we'll be seeing. I'll be asking her before we leave if she's got bras in her suitcase, and I am ready to leave her behind if she doesn't or make her go out and buy a few or buy them for her. What do I do? How do I handle this without alienating her but helping her to understand that something that is fine when you're out clubbing is not fine when you're trying to make a good impression with your boyfriend's family?

Prudence says: You have time to have a friendly and helpful chat with Dahlia before you all go bouncing off on holiday. Take a supportive, not punitive approach. You can say something like, "Dahlia, dear, you're young and beautiful, but the clothes you wear to go out in the evening aren't going to be appropriate for family outings. I wanted to make sure you have things to wear, including bras, that will work for the trip. If not, let's go to the department store and get you a few items." If you have to put the underwire, nipple-concealing bra on your credit card, consider it an excellent investment.

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