This is the first installment of three excerpts from the new book "Modern Dating: A Field Guide," by Chiara Atik, published in May by Harlequin. The next two excerpts will move May 23 and 30.

Unless you're living in some weird all-female city that I've somehow managed to never hear of, not all your friends will be women. Probably you'll have guy friends, too, who are great for serving as plus-ones when you need them, giving you the male perspective on your dating life, desperately trying to get you to see the genius in "Blade Runner," and occasionally helping you lug home an air-conditioning unit. However, they are not good for sleeping with. Do not sleep with your guy friends.

You know that Friends with Benefits never works, right? Of course you know that. You've no doubt heard someone, at some point, authoritatively claim that there's no way two people can have sex and still maintain a friendship.

And everyone is right, of course. It's incredibly hard to maintain a nice, even friendship with someone while also sharing something as intimate as sex - especially for women.

By starting a Frenz with Benz relationship (does the nickname make you less inclined to do it?), you're risking your friendship and your sanity. But whatever. You know this, but you might just go ahead and try it anyway.

Fine. Fine! Just keep the following things in mind, okay?

-Do not pick your best friend.

That guy friend who's like your brother, whom you've been friends with for years, who has seen you through countless breakups and has selflessly helped you move from at least two apartments? Oh my God, do not sleep with him. No! He's much too valuable, and the risk of hurting him (or yourself!) is much too great. Instead, choose someone who's on the periphery of your friendship group but not an integral member. Way less awkward when things eventually fizzle out.

-Do not pick the guy you're secretly in love with.

If you like him, tell him. Don't let him use you for sex under the misconception that you aren't interested in any sort of commitment or relationship with him.

-No one is Frenz with Benz forever.

You are not going to be Friends with Benefits with this person forever, or if you are, you should really consider upgrading him to at least "boyfriend" level. Friends with Benefits situations tend to come to a natural end when one of you gets a significant other, or moves away, or simply gets bored with the arrangement. You should both be very aware of this from the get-go to avoid hurt feelings later.

-If it's weird for you to talk about the other people you're dating, you shouldn't be FWB.

Doubly so if it's weird for you to hear him talk about his dating life. Being able to openly discuss the other people you're seeing (if any) is what differentiates Friends with Benefits from just being, like, lovers.

-It's Friends with Benefits. Not just Benefits.

Obviously, there's nothing wrong with having a hookup buddy, but Friends with Benefits implies some sort of friendship outside the bedroom. If you have any interest in maintaining this friendship after the benefits stop, be sure to spend platonic time together, alone or in a group, just like you always have.

-Avoid at all costs:

Set schedules, seeing each other five nights a week, getting annoyed at each other if one or the other doesn't call or text, any sort of unplatonic affection outside of the bedroom, any sort of "date" scenarios, telling other people you're sleeping together, prolonged cuddling, Valentine's Day.

If you start to feel jealous, or sense that he is; if you find yourself uninterested in anyone else; if you start keeping your nights free so that you can hook up with him: Please, for the love of God, check yourself before you wreck yourself. Are you falling for him? If so, you need to stop hooking up with him immediately and have a serious conversation! If at any point the two of you aren't on even ground, it's best to discontinue, if not the friendship then at least the benefits. Stop wasting time and energy having sex with this guy, and use it instead to find a relationship (all benefits included).

This is an excerpt from "Modern Dating: A Field Guide," written by Chiara Atik, and just published by Harlequin. Atik is a writer and blogger recently described by Gawker as "The Girl You Wish You Knew When You Moved to New York." She has been writing about dating for www.HowAboutWe.com, which provides a fresh perspective on dating, since 2010. Her writing also has been featured on Elle.com, Glamour.com, The Hairpin, Today.com, and Yahoo Shine.

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Text Copyright (c) 2013 by This Life, Inc.

Permission to reproduce text granted by Harlequin Books S.A.