In-Laws 🙄

Okay so my boyfriend and I have been together for 2 years now. When we first started dating things were kind of kept hidden. At the time I was a minor and he wasnt so we kept it hidden for a few months. The reason we kept it hidden is because my mom kept telling me "no he's to old for you" so I didn't want her to press charges or anything like that so I felt I needed to keep it hidden until I could convince her. Well she finally agreed to meet him and she loved him and now things are great. He gets along with my family so well and we hangout with them alot. On the other hand his parents are still mad about the fact we hid it (keep in mind that he is in his late 20s he is a grown adult). I just am so frustrated with them. Like I understand they feel betrayed but they have to realize at the time we were doing what was best for us. It's been two years and they are still mad about it. Like really? Of all people I feel like my parents should be the ones who are still mad?! It just makes me upset. Like I am sorry but it's in the past and we all just need to move on and live life now. It just makes me mad because they are holding a grudge that they need to just move on from.

Edit: I know they aren't my "in laws" but we are getting engaged soon so they will be. Also he isn't a predator, it just happened. I was almost 17 when we started dating. We worked together so we always saw each other and talked to one another. It was a mutual feeling. We get along great and are going to be together forever so.. I'm mature for my age always have been and he isnt 'typical' for his age. He is mature, just acts younger.

Edit 2: think what you want it's my life I just needed a place to vent because I have no one else really to talk to to get outside advice.