Why We 'Crush' on Our Significant Others' Best Friends

Crush on Friends
Daniel Fishel/Thrillist
Daniel Fishel/Thrillist

Here’s the Sparknotes version of my young adult life story: varsity cheerleader, college English major, resident of four different cities… and now, a 29-year-old, mostly mature woman living in Manhattan.

Each life chapter was shaped by many variables. Take, for example, the men I dated: selfish toads, guys with personalities akin to damp napkins… even a handful of great guys with whom I developed real, lasting relationships. I wanted to spend my time with these men. Impress them. Go out of my way for them.

So I'd go running with Mike and shoe shopping with Chris. I hit the gym with Alex, who taught me how to deadlift. And later, I designated Conor as my beer-pong partner. But I should mention that these guys weren't actually my boyfriends: They were my boyfriends’ best friends. And that’s because over the course of my dating career, I’ve had an unremitting case of Best Friend Syndrome.

What is “Best Friend Syndrome”?

Don’t bother looking up the definition on Wikipedia or WebMD -- it’s a term I’ve coined myself. Best Friend Syndrome (also known as BFS, because anything legit has an abbreviation) is the desire to spend time with and be viewed positively by your significant other’s best friend. Symptoms include: approaching him first at parties to chat and find out what’s new in his life, ordering him his go-to beer when you buy a round, and trying to impress him with your biting wit and easygoing demeanor.

I know what you’re thinking: Ooooh, sounds like someone has a crush! But I swear on my wine rack, feelings of perfidious romantic affection for a lover’s BFF have NEVER been the case. I was happy in my relationships and adored each boyfriend (at the time). And even though I’ve always been a confident girl, I’d be lying if I said I don’t care what people think -- because clearly I was striving for bae’s best friend to see the best version of me, too.

But why?

BFS is the real deal

As it turns out, BFS is actually quite common. “It’s normal to fixate and ‘crush’, in a sense, on your partner’s best friend,” explains Sameera Sullivan, relationship expert, psychologist, and founder of Lasting Connections. “You want to make a good, lasting impression on him so he tells your boyfriend that you’re attractive, fun, and the greatest girl he’s ever dated. Who wouldn’t want to hear that? It’s an ego thing.”

Think about your own best pal. The two of you likely share similar interests, values, and even personality traits. Your boo has chosen his ride-or-die for the same reasons and commonalities. Says Sullivan: “If he’s really talked up his friend, naturally you’ll look for all those amazing qualities and you may become intrigued by them as well.” I mean, obviously your boyfriend has great taste in people...

I asked my friends if they’d ever experienced BFS and their answers were just as I’d hoped: “Yes, all the time!”, “Oh for sure, I think everyone does that,” and “Now that you mention it…”

My best friend, who we'll call Anna, rehashed her recent relationship with a man named Nick for me. They’d been out on five dates -- enough to know there was mutual interest -- when they met up with his friends at a bar. “I spent a lot of time chatting and joking with Nick’s best friend,” Anna said. “They were a lot alike, so I enjoyed talking to him while also learning more about Nick. There was less pressure, too. He wasn’t the one I was dating, so it was easy to be myself and as an added bonus, get an ‘in’ with him.”

"In" it to win it

The "in" -- that was the end goal I was always after. I loved finding out from my boyfriend that Conor pulled him aside to say I was a perfect match; or when Alex finally trusted me enough to reveal that his best friend of 10 years called me "the one."

Anna agrees: “After I got home that night, Nick texted to tell me how much his buddies liked me -- his best friend even called me a ‘keeper,’ which made me feel good. Nick went on to say, ‘His opinion is so important to me and I take it to heart, so I’m happy he really likes you.’”

Because when you give the BFF reasons to vouch for you, it can only be good for your relationship with your partner.

Harmless intrigue versus real flirting

I never once wanted to dump a boyfriend for his bestie, actually flirt with one of these friends, or so much as imagine any of them naked. My end focus was ALWAYS on bettering my relationship with my partner. And maybe a little bit on myself, too -- because hey, I’m human and it feels good to be liked!

But the difference between BFS and deceit lies in your intention -- and here’s where the problems start. “It’s detrimental if you’re flirting with the friend for self-serving attention, or if you’re trying to get him to put the moves on you,” explains Sullivan. “Dreaming of having physical relations with him or ignoring your partner to spend more time with him are insincere actions that can lead to infidelity.”

True, you can’t help how you feel -- but you can be fair to your partner and take that moment to look closely and reevaluate your relationship. Because acting on such treacherous feelings is a condition that already has a name on WebMD -- Bad Girlfriend Disorder.

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Brooke Sager is a contributing writer for Thrillist living in NYC who has never experienced symptoms of Bad Girlfriend Disorder. Give her a follow on Instagram and Twitter: @HIHEELZbrooke.