A friend of mine and her husband (who also has a teenage son from a previous marriage) have had the same type of issues regarding inheritance, property, etc…so what they did was had the husband take out a seperate life insurance policy where his son is the only beneficiary to address the husband wanting to make sure his son got some inheritance and the wife to feel comfortable about her future if he should die before her. I recommend you speak with an attorney, since blended marriages are not at all uncommon these days, I would bet that an experienced attorney would have some creative solutions.