Vickie and Jeff marriage/kids question

I just saw the episode about Vickie and Jeff. Vickie was hiding a storage unit and a 9000 sq ft storefront full of stuff from her husband Jeff. The three adult kids knew about it but didn't tell him and he was ready to walk away from their marriage. I was confused during the whole episode because I couldn't tell if the kids were his from a prior marriage or if they were the biological kids of both parents. I thought they were Jeff's kids when - Jeff referred to them as "my kids", Vickie referred to them as "his kids" and it was mentioned that Vickie and Jeff were married for 25 years but one of the kids was 35 years old. On the other hand all the kids called Vickie "mom", she referred to them as "my kids" and they all resembled her more so than Jeff (they had her nose). So does anyone know what their story is? Is Vickie the stepmom?