After a bit of advice about how to handle this situation. Apologies for long post.
So a bit of history, DB has had various unsuccessful longterm relationships. He was married and divorced, then went straight into a relationship with next woman and had a child, niece now aged 7. They broke up after 5 years then he went straight into next turbulent relationship with new woman (with 3 children from previous relationship) who got pregnant straight away and he now has another child, nephew aged 1, they lived together for some time. They recently broke up and although he manages, the logistics of seeing both his children is difficult as they live over 1 hour apart. He works hard and fully provides financially for his kids but I'm sure this instability also had an affect on his kids who hardly get to see us, cousins and grandparents anymore. We have arranged a couple of days out during school holidays directly with the mums which has ended up with DB getting annoyed as it apparently infringes on his time he gets to spend with his kids.
Now DB is straight into a new relationship with another woman, also with 2 kids from previous relationship. Like with the previous woman's children, DB has already introduced his daughter and baby to new woman and her kids and daughter no longer has relationship with previous woman's children whom she previously referred to as her brothers.
He hasn't been single for more than 1 month since he was 17 so after last break up we talked to DB about prioritising his kids, being relationship free and focusing on sorting himself out with a house etc which he seemed to agree with. We have to tread carefully as DB doesn't take advice kindly and has fallen out with family members in the past due to his dramatic and turbulent relationships. Anyway 1 month later he breaks the news he has a new girlfriend. My parents made it clear to him that although they want him to be happy they are not interested in meeting any new girlfriends and I personally feel the same. Nothing personal against new girlfriend as we don't know her but we are all feeling mentally drained by DBs self inflicted dramas and feeling rather sceptical about new rushed relationship. I said maybe in a year if you are still together then maybe meet the girl and then later her kids. I and husband are also sceptical about our kids building relationships with another set of step cousins that they potentially won't see again in a years time.
2 weeks later he announces that he is coming over to our parents house with his kids, new girlfriend and her kids. Parents say they want to spend time just with him and grandkids on their own as haven't seen them for over 1 month. DB doesn't come and makes arrangements with new girlfriend and all the kids. With previous relationship he told me new women and her kids are his new life now so it is all of them or nothing. As she got pregnant we built a relationship with her and the children but that is all over now of course so we don't see them and vice versa.
Our parents are in their 70s and are overcoming health issues (much caused by stress from DB and worry about grandkids) and they now just want to relax in their own home without having to worry about meeting new people and children and dealing with potential dramas based on DBs past history.
What would you do
1 - welcome new girlfriend and kids into family and house with open arms, no judgements and hope for the best in order to see grandkids. Do this time again if relationships fail. Put up with the stress and dramas and deal with aftermath and questions from own kids.
2 - make arrangements with mothers directly to see the kids and risk big fall out with DB.
3 - stick to guns of not ready to meet new woman, unlikely any fallout with DB but also unlikely to see him and the kids and logistics of seeing them separately without new beau could be hard.
4 - wait nervously for news of another baby!!