I sat on the edge of my convertible on a gorgeous summer night telling stories with a girl who was one of my best friends in high school. I hadn't been home for more than a week in six months and we were catching up.

In the middle of an unrelated story, she uttered something that I had to actively try to ignore. It was a subtle, but deliberate, reference at one of the worst moments in my high school career. I overlooked it and let her continue with her story but with the utterance of that one sentence, the conversation shifted from lighthearted to tense.

She knew I probably wouldn't want it brought up again. She'd, for the most part, seen me through that turmoil in my life, but she made sure to remind me that she had not forgotten what had flawed me a few years ago. She is well aware I wouldn't want to be defined by that. She's also aware I've made long and deliberate strides to be a different person than I was then. Yet she couldn't resist the blow.

It got me thinking about what, exactly, you should do about those subtle digs. It was hardly outright sabotage as much as it was just enough to make me cringe and try to ignore it. It raised a red flag in my head that my gut told me was too important to ignore.

I'm no stranger to frenemies, which can run the gamut from untrustworthy acquaintances to backstabbing best friends, but I think the most unnerving kind are close friends who turn out to be untrustworthy. Frenemies usually have an undue interest in your weaknesses. I once knew someone who literally greeted me with questions about something she knew I didn’t want to talk about every time she saw me. Needless to say, she didn’t have my best interests at heart. But in this case, is a small insult thrown into an otherwise irrelevant conversation a subtle way of saying "Hey, I haven't forgotten seeing you in that less-than-graceful moment in your life"? I'm not sure if it was as outright rude as I had taken it to be, but even if it was a slight indicator of where our friendship stood, it still made me uncomfortable.

On one hand, in that situation, I know I would resist referencing something that one of my friends wouldn't want brought up. And something about it felt off. I thought about why I had chosen to ignore the comment. If I had said something, she would have retorted that I was being too sensitive, but as someone I’d known for years who’d seen me through the better part of my teenage years, she should be very well aware of the things that make my skin crawl.

For the purpose of this, I'm going to assume it was intentional. My first thought was that if you can't trust a friend, what purpose does that relationship serve? What is it worth that this same person sat with me on my basement couch several years ago talking me through something only to bring it up in subtle jabs years later after I'd left it in the past?

I can't really understand. It would be easiest to say that the best option would be to proceed with caution. To be aware of these things and to be cautious about approaching things that are sensitive to me with her in the future. But unlike people whose comments would be easy to dismiss, she’d known me for a really long time.

Is it realistic to think backing off a little is even an option we should consider? A gray area in any relationship is uncomfortable and usually a sign of doom. A happy medium in this case feels like a step back when someone has very well seen you at your worst. And that is one of the reasons I valued this friendship this is someone who had survived the better part of my teenage years with me. I liked that she knew everything about me and was still my friend despite it all. Those kinds of friends often serve a useful purpose of keeping you in check, but there's a distinct difference between that and intending to offend someone.

Friendships change just as our lives do and change is inevitable. But I learned in one telling sentence that they require constant work and a willingness to forgive and forget as we change with time. If your friends can't change and grow with you, maybe this backhanded, unsupportive behavior will eventually emerge. The feat of an enduring friendship is worth nothing if it’s something that could serve the purpose of bringing you down.

In my experience navigating the often-confusing ground with frenemies, I've learned that the people who are the most inclined to hurt your life are the ones who don't understand why and where your life is at a given point in time. And maybe this is a way to keep ourselves in check, to make sure that our friendships are reflective of who we today, and who we want to be tomorrow.