Parents and Husband (Long rant - advice please)

My husband and I have been married for a couple years. We are expecting our second baby in June and our 18 month old is the light of our lives! We went through some hard times about a year ago when my husband got arrested and a few months after I found out he had an addiction. We lived with my parents for awhile as we got to a better place in our marriage and we are now living in our own home and are very happy. It took a lot to get to where we are, but I'm so thankful we pushed through and he's at a much better place now. My parents helped out so much and always have been such a wonderful support system. They're the kind of people who help family no matter what and I am so thankful for everything they did for us. Before my husband found this job, he was working for a company for about a year and his boss treated him wonderfully. He helped us out with court payments and things that we couldn't handle at the time, but we always had payment arrangements and owe him no money. We were super thankful for his help and providing my husband with a great job and in return he was a wonderful employee to him and brought in a lot of money to the company. He didn't treat his employees very well when they would quit, so my husband gave him plenty of notice and didn't go into detail about what he was going to do next and everything ended on good terms. He even told him that he could come back and work for him. One of my husbands coworkers there was an old family friend of mine and they didn't get along very well. He recently went to my parents and told them that my husband made up this huge lie about his uncle supposedly dying and him needing to go help out the family business and that he would be back in theee weeks. My mother then drove down to her son in laws previous employer after hearing this to talk to him. She just called and let me know yesterday and his boss had all sorts of stuff to say about him. He told my mom that he borrowed money all the time, he made up that lie about what he said when he quit and the list goes on and on! Now my parents are calling me telling me all this stuff that he said about my husband and they believe all of it. They're acting as if my husband is a huge liar once again (and yes that trust was broken when he was using and it has taken us all a long time to get to a better place), that he's using, that he took off with his boss's money and that we are going to be taken to small claims court now because we supposedly owe him money is what he told my mom. If we owed him money, he is easily able to contact me if he needed! And I can't get over the fact that my mother went down to his old work to talk to his old boss! How would she like it if her mother in law did that to her? Isn't that completely out of line? I understand that they want to be protective and helpful, but in reality he is my husband. It's our marriage. If anyone should have gone to his old boss, it should have been me as his wife if there were huge concerns! Do you think my mom overstepped? I can't believe she did that. I love them and appreciate hem wanting to be helpful and supportive, but at the same time this is our life and I am a grown woman! My husband is a grown man! Even if he did lie to his boss, that doesn't concern them! They are assuming the worst and I think they were just waiting to "find out something like this so that their worries or doubts could be confirmed. It's hard for me to trust my husband still, but he has worked so hard and grown so much after getting clean. He might not do everything as I like or my parents like, but it's not their life! He's not their son who is under 18 or something like that. I'm so angry and upset and feel like they won't believe when I tell them everything wasn't true that his boss said. I'm not a confrontational person at all, but I know I need to stick up for my husband and our marriage.