In this instance with Twitter user @PamTina_, her "annoying" kid brother was the former: absolutely wholesome and pure.
When Pam's younger brother discovered that he and his sister aren't "fully" related, his reaction was an adorable one.
It moved her to tears and left a huge impression, so she decided to share photos of what her brother did on Twitter, where everyone was absolutely in love with his reaction.
Growing up, my older brother would joke that I wasn't really a part of the family: that our mom and dad found me in a garbage can and felt bad for me.
Although I knew he was probably lying, there was still a time period where I believed him — and it got me thinking that he and I are weren't actually related. Which was a bit comforting at the time, considering how much we were at each other's throats when we were younger.
I definitely wouldn't have given my older brother a whole bunch of his favorite snacks, like Pam's brother did, if I'd found out we were half-siblings.
And I most certainly wouldn't attach a heartfelt letter, either.
Her younger brother's message was an adorably sweet one — he tells Pam, in light of his discovery that they aren't a fully biological brother-sister duo, that no matter what, how he sees her and feels about her hasn't changed at all.
They're 100% siblings in his book, for better or for worse. Here's his letter in full:
"I just wanted to let you know how much I love you. I don't care what people say, you are always going to be my sister — my full blooded sister. You are the best thing that happened to me, I love you with all my heart. Thank you for helping me on my worst and thank you for leading me the right way. I will always be there for you, just like you always been there for me. I love you.
Your annoying brother. <3
People were floored by her younger brother's reaction and got a bit emotional themselves after seeing Pam's tweet.
The tears were flowing for real.
Some shared stories of their own sweet younger sibling encounters.
And some of the encounters weren't so sweet.
Like this one woman who asked her younger brother why he didn't show her love the way Pam's brother did. The response she got was great, but for an entirely different reason.
And although Pam's interaction with her younger brother was absolutely heartwarming, we all know that different people show love in different ways.
If it's purity you're looking for, then this guy's story about his 8-year-old brother who just learned how to text will melt your heart.
Or take a look at this girl's older brother who pranks her mercilessly at every turn.