Being their 16 year old sister and them finding out you have a boyfriend (Gotham preference)
Bruce has always been very protective of you, especially after your parents died, he can’t stand the idea of losing you too. When he found out you had a boyfriend he pretended to be cool with it but he actually ran a background check on him and followed him around for a few days to make sure he was good enough for you.
Selena is pretty easy going when it comes to you dating. She’ll tease you about the guy but at the same time if he ever broke your heart she would gladly kick his ass. She also wouldn’t have a problem using Barbara and Tabitha as a scare tactic to keep the guy in line.
You are the only person Barbara knows for a fact would never betray her so she does everything in her power to make sure nothing bad ever happens to you. The first time she meet’s him she insists on it being at her armory so he knows exactly the kind of fire power she has in her possession.
Like Selena, Tabitha is pretty relaxed about you dating but she does find pure entertainment in scaring the guy. She’ll pull out her whip and crack it right next to his head (or right in between his legs if she’s feeling extra nefarious that day) and tell him gruesome stories about all the guys skulls she bashed in before.
When Ivy found out you had a boyfriend she was beyond thrilled. She loves romance and gets excited whenever you ask her for advice. She snoops around in your relationship a lot because she loves knowing all the details. She loves teasing you about how cute you two are.
Although he would never admit it, Oswald can get a bit jealous and is afraid of this guy taking you away from him. He makes sure the guy knows fully well that if he ever hurt you he will have Victor to deal with. Oswald will ask you about him all the time to make sure he is still treating you right.
Ed has a more logical approach to determining if he likes your boyfriend or not. He will put him through a series of tests and if he doesn’t pass he goes on Ed’s watch list. Ed is pretty vocal about the fact that he believes you only deserve the best which to him is someone who is as smart as himself.
Alex is just happy to see you happy. He will invite your boyfriend to study with the two of you all the time. He likes hanging out with you both and you spend a lot of time with him at your grandfathers shop.