n. def. Public display of affection. Feeding your lover Lucky Charms in the middle of the annex at Val, making out in a crowded social dorm basement, sitting in your professor's lap during office hours (just kidding-whatever gets you the "A" is fine by us!), etc.

XY: It would be disingenuous to pretend that we thought this one up ourselves. So, whoever put up that very clever sign in the Valentine coat room (you know, the one decrying such loathsome practices as licking your lover in West)-we salute you.

XX: Licking anyone outside the bedroom is loathsome. However, we need to distinguish between different types of PDAs. Some PDAs are acceptable, others are sometimes okay, and then there are the ones that are just wrong. Wrong for you, wrong for me, wrong for society.

XY: Well, obviously hand-holding is pretty innocuous-

XX: -unless you're actually in a classroom or you're running on the bike path and sweating like pigs. That's just gross. But yeah, hand-holding is fine, in general; this column is not meant to be polemical, but rather didactic-

XY: -and once we've taught you vocab, then we can address PDAs. I guess a logical starting point is where, when, and most importantly, how can you kiss in public?

XX: I think a peck on the cheek or the lips (but not the neck!) is fine almost anywhere (again, not in class). But when it comes to a more serious brand of kissing, the rules get more complicated.

XY: Do not be like Mike (Michael Jordan, that is). Unless you're dropping 35 on the Blazers in the first half of the '92 Finals, leave your tongue in your mouth. But hey, if you're intrepid, go ahead-just try and cop a feel without someone noticing. Because if I see you, I'll laugh. And point. And call my friends over.

XX: So in public, you should never make out using your tongue; there are plenty of private spaces on campus. (Write in, and we'll elucidate further if necessary.) Also, keep your hands more or less to yourself. A quick squeeze of the thigh under the table (furtively, of course) is fine, but a hand job or a lengthy massage is a no-no, be you at Valentine, Schwemm's, on the steps of Frost or wherever there are virgin eyes present (hey, you never know!).

XY: Yet-paradoxically?-I don't so much mind people sitting in their significant others' laps. Call me Che, but that's a pretty harmless breed of intimacy. So long as there's no surreptitious grinding, I mean.

XX: I exaggerated. I didn't mean keep your hands to yourself; what I really meant was, don't launch your boyfriend's pocket rocket in my presence.

XY: Good, we were beating around the bush. It was time we took a firm stance against the hard-on (cheap pun? abso-fucking-lutely). Now, we understand there are those of you for whom the danger of getting caught is a turn-on. (You're the ones checking out "Crash" from the Media Center.) But exhibitionism and PDA's are two completely different beasts.

XX: Agreed. Exhibitionists thrive on the danger of getting caught, while couples canoodling are more or less oblivious to the fact that they are getting caught.

XY: As for parties, I bet that if you're emitting aphrodisiacs strong enough to convince a girl that she wants to make out with you on the dance floor, you can probably get her back to your room. Or at least to the bathroom (though the bathroom rendezvous is a whole 'nother column).

XX: A few moments of lip contact (and maybe a little-the tip-of the tongue) are okay, as a teaser or whatever, but when you're really getting into things, disengage. Unilaterally, if necessary. Face it: Sometimes, you'll be the observer. Yes, you, Casanova.

XY: And when, you wonder, is it time to disengage? This is my rule of thumb: when your flag is flying high, it's time to say goodbye. Or "Come back to my room."