I don't blame you, I've already told my DH that if he dies first, I'm not leaving most of what's left to his son, as our current will states. At most, I will leave it in equal shares to our 9 nieces and nephews and SS. But - he agrees with me and said that was fine. How will your wife react?

An attorney can explain your options, but if your wife has ownership rights to the properties, she has some say, too. 

Someone who specialises in this area of wills and trusts.  I'd be inclined to set up the will so that your DW gets the property in trust and benefits from the income during her life time.  Then when she passes, you can split where the estate goes.  You don't sound like you want to give yours to your own kids so you'll need to pick a worthy cause to get the inheritance.  You just need to remember that your DW will probably want her share of the estate to go to her kids and you'll have to accept that.

Second marriages and inheritance is complicated. In my state property owned before marriage, if kept separate, is controlled by the person's will. Property acquired after marriage depends on how it is titled. If the property is titled jointly, it goes to the joint owner and cannot be willed separately here.

As you know, you need a lawyer to sort this out. Going to a lawyer by yourself is a good idea. You need to understand the possibilities and options before you discuss this with your wife. Have you considered a post nuptial to put in writing whatever agreement you come to with your wife? (I recommend a lawyer for you and one for your wife.) You both would then make wills that reflect the post nuptial. 

I have an investment property and 2 biokids with my DH and he has SD. 

I do need to set up my property in a trust for my kids, I had it before getting married so its alline to do with how I wish  However as of now I trust my DH wouldn't let SD have any benefit from it, he would probably sell it. But yes, you need to set up something otherwise your kids probably won't get anything.

I guess the first thing you need to do is figure out what you want to happen with your estate.  Who do you want to benefit from it? If not her kids ultimately.. OR yours.. what would you do if the tables were turned?  If you inherit it all.... who or what would you leave it to?  A charity? A distant relative? A friend?

Depending on laws where you are, it's posible some kind of trust arrangement might work.  Perhaps the assets could be in trust and she could benefit from the proceeds while she is alive and when she passes, the assets are then distributed to some ultimate beneficiaries.. a charity or a school or your nephew Bob...?

You will need legal/financial advisor help with this.  It may be that you can have just your portion of the interest in the properties in a trust.. or it may be that you both need to do something like that...jointly agree to it?

I was in a similar dilemma.  When I married DH I owned my home.  10 years ago we bought a house together and both paid 1/2 of the initial cost but I paid an additional $55,000 for improvements.  DH owned 1/2 of our home but had no savings to speak of and didn't seem too motivated to contribute to a savings plan.  I had been more diligent in putting money away.  I couldn't help thinking of how unfair it was that if I died my interest in the house and possibly my hard earned savings would be going to SD who despised me.

Last year I made out a trust to protect my assets.  Later I got a postnuptial agreement - but by that time I was thinking of divorce.  You never know what will happen tomorrow.  We sold the house we both owned and each got 1/2 but DH made out far better than I did on the deal.  Luckily, I always kept savings in private accounts so when the divorce is final I will still be OK.

If you are thinking of getting married take a long, hard look at your financial compatibility and expectations before taking the plunge.  It might seem cold but it is realistic.

As you seem to already know, you need a lawyer.  And yes, you'll need to create a trust that the assets are titled in.  I am not sure if the rental properties would be titled in a trust, or an LLC that the trust has ownership of, but the lawyer should be able to figure it out.  Then if your wife dies, the assets stay under the trust (or LLC) for your lifetime.  Then after you pass, it gets split 50/50 with her half going to her kids and your half going to whoever you like (maybe a charity).  Same if you pass first - assets stay titled under the trust and you benefit from them for your lifetime.  After you pass, they get split 50/50 again as you both direct.  Or something like that at least :)  Good luck.

It'll go down better if you found a person or charity you support and phrase the conversation so that you emphasise how much you want to take care of her after you're gone but ultimately you also want to contribute to the charity that means so much to you when she no longer needs the money herself. And then set up a trust to provide for her while she's alive. It'll sound better than "I don't want your spoiled kids getting their hands on my hard earned money" even though you're technically working towards that same goal.

Portion to whomever, or whatever you wish. No spouse can speak for the other's finances UNLESS you've agreed to that.

Who else would you leave your assets to since your kids don't speak to you?

You could always stipulate how it is doled out, over time or lump sum.

Yes, meet with an attorney and get professional advice. 

Where do you live, Pete? That can make all the difference. Inheritance laws vary depending on the country. NZ, OZ, UK (and even then, the laws are different between Scotland and England, for instance)? 

Sort it out legally, fortunately my dh and i agree on how things should be sorted tbh, im more for giving the skids their share than he is.  but my only condition is. they get it when im gone and not before if he goes first.  butputting it all in place is time consuming and costly.