i've been dating my boyfriend so long & i still can't barely go to his house

i've been dating my boyfriend for 3 years now and i'm still not allowed to go to his house only if its for his birthday but i have to bring my brother. I'm 16 and so sick of it i get they don't want me getting pregnant but i wouldn't do anything like that at his house because his mom is home. I've have in the past in middle school sneaked him in my house alone and gotten caught, a bunch of times but i've change and they still don't trust me. that was when i was 15 i'm different & i don't know what to do to earn the trust