What did harry see while hiding in the cabinet at a shop in knockturn alley?

Hello i’m a florida 16 year old female, turning 17 in august and my boyfriend in 17 turning 18 in august as well a couple weeks before my birthday. it’s currently june 3rd, i told my mom today that i am dating him. we’ve been dating for about 5 months. i told her out of respect because i didn’t want to hide anything anymore. she said that he will not be welcome in our home, she does not want to meet him or his parents, she will get police involved if she has to to make sure he stays away from me. if she does get police involved will he get in trouble and did i do anything wrong? i’m familiar with the romeo and juliet law and don’t think we’ll get in trouble but i need reassurance.