Thank you for your quick response! To answer your questions: The divorce was finalized in January 2012 but they had been talking about divorce/severely struggling for about 4 years. His "teenage" behavior started in March/April of 2012, so fairly quickly after my mother moved out of the house. What I meant when I said it was not a bad divorce is that in the settlement, my dad kept the house with most of the furniture(net worth 130k) and he wanted to give ALL of his retirement to her (net worth 220k). He was very generous in my opinion as far as settlement is concerned.
Anyways, next. My brother is bothered the most and asks me if he should tell him to stop or what he should do, if anything at all. We have agreed not to tell our mother because we didn't want her to view/treat him differently because of insider info per say. I believe I hinted to my mom a while back(8 mo.+) about his love poetry; and she said he has always been a sensitive and loving man. And that he truly enjoys playing the guitar and writing lyrics/poems, so he is probably just spending more time doing so. But this is different because he sounds more like an immature boy, almost to the point that I am reminded of teenage girl feelings.. I don't want to hurt his feelings because he doesn't have any true friends outside of his work colleagues and I don't want him to feel abandoned by the only people/family that he feels he can speak freely to.
I just found out this morning that he is seeing someone and he feels it is/can get serious like marriage. He had called me on the phone and told me he has been seeing her for almost 6 months and that she works in a separate department at his work. This shocked me, and I told him to be cautious and take things slow because it is easy once you have been alone for a while to really want to "throw it in 5th gear and floor it" with new relationships that seem excellent in the beginning. He said I was right and that he will keep that in the front of his mind. My brother knows about her, as of today, and my mother does not. He asked me to keep it that way. I don't like that he has jumped into a relationship, let alone a "serious" one so soon, however I know that my parents had a "cold" relationship for quite a long time. they haven't slept in the same bed in the last 8 years.
Honestly speaking, I just want him to be back the way he used to be. My brother and I are not the kind of family to disown or shut-out our loved ones and will never be capable of doing that to our dad. If I don't get my old dad back, I will just be unhappy about it and worried for him for as long as he remains this way. I think my brother feels the exact same as I do.
He has many medical issues but is an attractive man and very nice. I can see other women accepting his "medical baggage" and loving him; I just don't think it should have happened so quick. Maybe it just seems quick to me? Who knows.