Auntie SparkNotes: No-Tell Bro-Tell

Dear Auntie Sparknotes,

I am a terrible sister. To explain: Last summer, I ended up hooking up with a guy who I really liked, and I thought liked me too. He became my first HND. Let's call him John. The trouble is that John was, and remains, my brother's best friend. John expressly forbade me from telling anyone about us, because he didn't want my brother finding out and getting mad at him.

Well anyway, after about a week of together-ness, he turned out to not be as great as I thought he was... or as single. (He had a girlfriend, and I have a sneaking suspicion that he had several other ladies that he was being "friendly" with at the time. Ugh.) Now, my brother and I have never been super close buddies due to the age gap, but I love him and we've always gotten along. I haven't told him about any of this, but I feel like sleeping with the best friend is one of those things that little sisters aren't supposed to do. Should I keep quiet and wait until he finds out, if he does? Is this really not all that big of a deal and I'm just overreacting? Is this none of his business? Or is this something he's entitled to know, seeing as it's HIS friend? He's usually pretty protective of me, and I don't want him to hate me. I'll see John again in the summer, and since last time I saw him he ignored me like he was getting paid, having him hang around the house might be a tad bit awkward. My brother is coming home from college soon, should I tell him then?

GAAAAAHHHHHHH! NO NO NO NO NO NO NO! NOOOOOOOOOO!

...Er, sorry there, Sparkler—the top just blew off my brain's Freakout Box, and a whole bunch of yelling came out! Bu—and I don't think I can overstate this enough—the answer is no. No, this is not your brother's business. No, he isn't "entitled" to the details of your sex life, no matter who your partner is. And no, you should not plan to greet your Homebound Bro at the door with a loving hug and the confession that you schtupped his best friend.

So please, before you do anything else, stop wondering if you're morally obligated to 'fess up to your hookup; the only reason to tell your brother what happened is if you, personally, want to talk to him about it. And yes, if you tell him, he'll probably be less than thrilled. But that's not because The Laws of Human Decency contain a hard-and-fast rule about not sleeping with your older sibling's best friend.

It's because they contain a hard-and-fast rule about not being a slimy, lying sleazebag who cheats on his girlfriend with his best friend's little sister.

Which is why this dude swore you to secrecy, and which is where your problem lies—a problem that has nothing to do with the fact that this guy is your bro's BFF, and everything to do with the fact that he's a grade-A specimen of the species douchebaggus enormicus. Or in other words, it's not that you're a terrible sister; it's that he is a terrific, record-breaking, platinum-plated a**hole.

And that's why it's well past time that you stopped beating yourself up for someone else's atrocious behavior. You're not at fault, here; he's the cheater, he's the liar, and he's the one who's handling the aftermath of your hookup with all the maturity and aplomb of a twelve-year-old. And in addition to recognizing him for the pathetic tool that he is, please also give yourself a big pat on the back for being so comparatively cool-headed and savvy about your disappointing first foray into Sexland. Because while losing your V-card to a person who turns out to be a jerk may not be one of life's most fabulous experiences, it isn't the end of the world—and the next time you're ready to get busy, you'll know better than to do it with one of your brother's besties.

Not because it's wrong, but because your brother clearly has terrible taste in friends.

Have you ever hooked up with a sib's friend? A friend's sibling? A friend's sibling's friend? Tell us in the comments! And to get advice from Auntie, email her at advice@sparknotes.com.