Ex still not over me?

We were teenagers that dated for 3 years! We both cheated on each other and just had a unhealthy relationship. We always argued and both thought that we were right. He went off to boot camp and we were already broken up.. Once he ended up stationed in California he wanted to see me and I wasn't sure about things. He offered to fly me to California and buy me a house etc.. 2010 But I ended up going on a trip to see a friend instead which is where I met my husband. I haven't heard from my ex since. About a year ago 2015 i had a bad dream about my ex getting blown up while deployed. It was weird because I NEVER have thought about him so I was worried for some odd reason (he was my first).. I text his number from high school that I had memorized and responded and he called me. We both found closer and he was deployed which was scary. My husband said it was fine but don't talk to him again and he 100% trusts me. My ex is married and I'm married with 3 children I told him thank you for the closure and to not contact me ever because we don't want to upset our spouses because I'm madly in love and respect my husband. Here we are in 2016 now and he has texted me twice just a hey what's? And a is everything okay? I didn't respond but why is he messaging me when we agreed not to talk! I told my husband that he text me and that I didn't respond but at the end of the day I'm curious why he is still thinking about me to text me! So frustrating because there will always be a place in my heart for him but I'm not in love with him!!!