Hey guys, please get back to the topic. TS, i have almost similar case, but slightly differ. I would recommend,
1. Do NOT tell your mom (Take care her feeling, old folks think a lot)
2. Ask your dad, what he plan / wanted to do (He need to responsible to what he had done, at least from my view for sure allocation of asset should be fair enough to your mom), often none given cause brainwashed by mistress.
3a. If he seems doesnt care of your mom anymore, so do u and your siblings. Let him enjoy his life as long as he never bother you, siblings and mom.
3b. If he care about your mom, then u may still look after him after this.

*No point arguing with him, he will come out with excuses like, i had hard time bringing u guys up and yet u guys abandon me, etc etc. Everything is too late for argue,quarrel or even discussion. Just make it straight to the point. What he WANT, what u WANT. Thats all.

@jayc: I agreed with n00b13. Its almost impossible for that to happen. This only happen to those rich / capable to take care both families, but rarely happen.
To TS: I dont care what others said/argue for u here, but i STRONGLY encourage NOT to tell ur mom on this. Old folks retired have nothing to do, and end up think more and more. Remember, once broken it will never be the same anymore, just like piece of paper or mirror/glass. There is no cure for broken heart at this age. And i hope that your family will not opt for divorce, they have been together for so long, for god sake, please dont let their marriage end in this way.

This post has been edited by WallChecker: Jun 19 2012, 04:44 PM