You had moved into the home of your step-family with your mom a week ago. You hadn't used your quirk around them yet, and your mom was strangely quiet about it; normally, she would've went on and on about your quirk and how it was just like your dad's. But you figure she wanted to wait to tell them all, which to be honest was still very weird of her to do. So you wait a bit to use your quirk, just getting settled into your new home with the step-family.
One day, you are working out like usual. You are out of the house at the local gym, so you decide to use your quirk here - the space was made to help people train, after all. So, you use your quirk a bit to strengthen it. Unfortunately, one of your step-siblings passes by the gym and sees this. they take a video of you using your quirk, then sends it to the family group chat. Of course, you have your phone off so you don't get the notification.
After being at the gym all day, you are exhausted but feel good about getting back into your training. But, when you enter the house, you notice something strange. Your mom is crying, your step-dad looking pissed. And your step-siblings, they look downright gleeful but not in a good way. this feels wrong, your senses telling you that something bad is going to happen. But a hero should not be scared of facing danger, so I close the front door and greet everyone.