I know my "step"mum took my Dad to redo his will within months of them marrying.
Not surprisingly that when my Dad first left my Mum, he wanted a relationship with both me and my brother (who were wary, as my Dad is not always a nice person) but 14 years later, he hasn't spoken or made attempts to for over 2 years (for me) and 5 years (for my brother). We tried for ages, but we always had to go through her, or whenever we saw my Dad she had to be there, which was fine initially but whenever we did, it was all about her - where she wanted to go, what she wanted to drink, she'd get drunk and loud and embarrassing and sit between my Dad and I so we couldn't actually talk anything other than idle chit chat. She'd get my Dad to ferry her kids to parties and University but they moved across the country so the only time I could see my Dad was once or twice a year.
The last time I saw my Dad he looked exhausted with her behaviour and had lost a lot of weight - she'd happily pig in but tell him to watch this and that and don't drink too much etc etc. After that, I had a breakdown and she screened all my Mum's attempts to contact Dad - eventually an email appeared in my inbox saying "Fed up of your bullshit" (I had a long battle with ED and MH) which was suspiciously written nothing like my Dad's usual e-mails.
She's got form for this - married twice, nobody knows about her first husband but the second is the father of her children and sends her an allowance (note, not child maintenance) per month. My Dad is as much to blame for this, but I can't help but think he's been duped - within a year of getting together, she'd got him on the mortgage and stopped working, made him buy another house and a holiday home in Ibiza (he always hated stuff like that?) and a sports car.
Even if we expected an inheritance, which we don't despite my Dad's six figure income, we are sure as shit she's either spent it all already or they are up to their eyeballs in debt enough for it to be obsolete. It's pretty disgusting, really.
(Incidentally, I'm now a stepmum with a child on the way, and my life insurance/works policy is split between DSS, any further children and my fiancée - DSS comes as the package of our family, whether he came out of my vagina or not)