My fiance and I have been together for almost 2 years. We are a blended family, together we have 3 children, I have an 8 year old and he has two children ages 6 and 4. We have my son full time and we have his part time. He has joint legal and physical custody of his two children. We have his children almost every weekend and for the whole summer full-time and every holiday as their Mom always works holidays. We take them anytime she needs us to.
His Ex is pregnant right now and is not married and not in a relationship. The father to the new baby does not want the baby; he even offered to pay for an abortion. He wants to sign away his rights. She is disappointed about this but still wants the baby.
My fiance and I realize the new baby will be a half sibling to his children and we would like to keep them together and help her out.
So we have offered to help her, by caring for the baby on weekends when we have his two children so she can work.
My questions are: is this a good idea or is it a bad idea? Would this be confusing to our 3 children? Are we just setting ourselves up for heartache as she could put an end to us watching the baby at anytime?