My boyfriend's parents aren't fond of me (they don't know we're back together).

My boyfriend (29) and I (28) have been together for 10 months now. We previously dated in high school for two years and were each other's first loves and experiences. Back then, I was dealing with mental health issues and addiction, which led to me hurting him deeply. As a result, his parents don’t like me, and he’s aware of that. He hasn’t shared our current relationship with them because he wants to keep both our relationship and his family connections intact. Every time his dad visits, my boyfriend has to remove all our photos and anything I’ve given him from his house. It’s painful, but I understand that revealing our relationship might strain his ties with his parents. He’s shared with me how much it hurts that I can’t attend family gatherings or holidays with him. I often think about our future—marriage, living together—and it feels daunting given the current situation. He mentioned recently, during a conversation on this topic, that “my dad’s going to find out eventually.” I feel so lost about what to do. He feels like my soulmate and best friend, and I envision a future with him. However, it's clear that moving in together isn't feasible right now. I’m considering writing a letter to his parents, but I’m unsure. TL;DR: My boyfriend and I reunited after 10 years apart; we dated for two years in high school, and I hurt him then, which led to his parents disliking me. They don’t know we’re dating now. What should I do?