It's a Wednesday night. You decided to finally try out that "mayo as a hair conditioner" trick women's magazines periodically trot out as a folksy, money-saving remedy for straw-like locks. You're slathered up, clad in your PJs with the bacon grease stains on the front.

A high-school mix CD you unearthed during a feeble and incomplete attempt to clean out your junk drawer is on the stereo and 4 Non Blondes is unapologetically blaring. Because you really like to party, you're simultaneously watching this week's 29th live hour of "So You Think You Can Dance." Unexpectedly, the doorbell rings.

You use your peephole for peeping and see that it's your new beau come a-knockin'. It's only been three dates -- he's dropping in already? What to do?

If Emily Post were doling out advice, we'd be living in an era in which your servant would answer the door and take the young man's calling card before telling him if you're receiving visitors or not. You'd also be sitting around the house in a corset, working on your scrimshaw.

Before the advent of the phone, pretty much the only way to see someone was to pop in. The traditional rules of etiquette say you should politely greet your guest as though you're not mortified by the situation and then gently ask that he call first before dropping by next time. That way, as you should tactfully explain, you can be sure that you complete your evening's activities (e.g., home bikini wax) and be able to fully devote your attention to him and his company when does arrive.

A more modern approach would be to turn out the light, pretend you're not home, wait for him to go away and then act like you have no idea what he's talking about when he asks you about it later. Let's face it -- no good can come from opening the door.

It's nice that he wanted to see you and all, but there's plenty of time to witness you in all your disheveled glory should your relationship progress beyond date number four. Miss Manners will back you up on this. In her "Guide to Excruciatingly Correct Behavior" she cautions that "Under no circumstances should one let an untimely visitor cross one's threshold." Amen.

Best mode of survival is to simply play dead. At some point in the future, work into the conversation about how you dated a guy once who loved the pop-in, and then mention what a loser he was. Hey, it's not the most polite thing to do, but neither is dropping in uninvited and unexpectedly.