Me and my girlfriend started dating about 2-1/2 years ago. She has a boy from previous marriage and I have one daughter from a previous marriage. About 6 months into our relationship she got pregnant, although its not what we wanted, I had promised her that I would be there for the baby. Then she had a miscarriage which pretty much tore us both up. We stayed together for about another year, then called it quits between us. Well that didn't last but 2 months and we started talking again. A month later she misses her period and yep, she's pregnant. I questioned her if she had been with anyone else, and she admitted that she had one night with a guy right before we got back together but there was no way it could be his. So during the whole pregnancy I had doubts, but I also believed her when she told me it had to be mine. I was out of the country and couldn't get home in time when the baby was born, she had already been discharged from the hospital by the time I made it there. Although we don't live together, me and my daughter spent alot of time at her house the first month with the new baby, everyone was excited and everything was going great, marriage was being discussed. But those doubts were still in the back of my head so I decided for my own peace of mind to have a DNA test done. Got the results back, I am not the father....the one other guy has been tested and awaiting results now but we all pretty much know what it's going to be, and he has already made the statement that he did not want anything to do with the baby.
So here we are now. My daughter thinking she has a baby sister, I was thinking I had a new baby girl. I haven't had my daughter back at her house since I found the results out, I told her that they are out of town, but that's only gonna work for so long. Me and my girlfriend are still talking as of now and I still go see the baby, after being by her side through the pregnancy and there with the baby everyday the first month, I must admit I am attached to the baby although now I know it's not mine, it's hard to just stop seeing and caring for the baby.
Any advice on what I should do? Especially with my daughter, I dont think she will understand right now, she's only 6. I love my girlfriend and don't want to leave her but at the same time I am afraid of what could happen in the long run as I get more and more attached to the newborn baby. I honestly believe that she is sorry for what she done, but I am kinda torn between leaving her or staying together helping her raise a baby that is not mine. Any input appreciated.