If you are looking for an academic angle on the concepts mentioned (obsessive behavior in siblings or friend groups), you might look for papers on Sibling Rivalry or Attachment Theory in psychology journals, though they will not reference that specific username.
A sister who has watched the protagonist from afar for years. The Calculated Move: phatassedangel69 best friends obsessive sister better
"Hey, I wanted to talk to you about your sister. I know you guys are close, but I've noticed she's been really obsessed with your friendship with [phatassedangel69]. I get that she cares about you, but some of her actions seem a bit over the top. Have you talked to her about how you're feeling?" If you are looking for an academic angle
Just then, Leo walked in. He saw his sister’s crazed eyes and Chloe’s calm, cool confidence. In that moment, the "better" choice was obvious. He didn't need a curator; he needed his best friend. I know you guys are close, but I've
, the "better" element usually implies a comparison—suggesting that the connection with the sister is more intense, "better," or more rewarding than the friendship or any previous relationship. It’s a classic "grass is greener" scenario that drives the plot forward through conflict. 4. Community and Serialized Fiction Platforms like X (formerly Twitter)
: A popular choice featuring a lifelong crush on a best friend’s older sister that turns into a whirlwind romance when she returns home. The Secret to Dating Your Best Friend's Sister by Meghan Quinn