My wife gave birth to a (biracial)baby that clearly isn't mine, and I'm divorcing her. But I'm worried about the relationship between my two kids and their new half-sister.

A month ago, my wife gave birth to a baby girl. But after the initial happiness of having a newborn wore off, I started to think that something wasn't right. <br><br>First of all, our newborn baby was biracial and had noticeably darker skin than my wife and I (we're both Caucasian). I've always wanted to be a father, so I decided to adopt the child. <br><br>After all, my wife was absolutely thrilled to have a child of her own, so I decided that I could adapt to be its father. After all, families come in different shapes and sizes, and this one just happened to be a little more complicated.<br><br>However, my wife was not on the same page. When I offered to adopt the child, she became furious. She barricaded herself inside her room and refused to come out. It got to the point where I just wanted to leave her alone for a while to calm down.<br><br>However, things only got worse from there. I woke up in the middle of the night to find her packing her bags. She told me that she couldn't stay here anymore because I wouldn't accept our baby "for who she is." <br><br>Naturally, I was very confused. I had just offered to adopt our baby, so I didn't know what else I had to do to accept her. So I simply asked her to tell me what she meant by that. Her response floored me. "You know exactly what I mean. You know that this isn't your child, and you need to accept that I cheated on you."<br><br>Hearing those words hurt more than anything else she's ever said to me. I felt like I'd been punched in the gut. I had no idea that she had cheated on me, and I felt betrayed. I wanted to know who the baby's father was. But when I asked her that, she told me that it was none of my business. I couldn't let that go. So I kept pushing for an answer until she eventually told me that she'd had sex with one of her coworkers. She told me that she had been having an emotional affair with him for months, but had only been physically cheating for a couple of weeks. <br><br>When I heard this, my world came crashing down. I felt like I'd been blind-sided. I never expected her to do something like this. When I looked at our new baby, I just felt betrayal and sadness. I didn't feel any paternal love for the baby. And when I thought about our two sons having to grow up with this baby, I felt worse. <br><br>The three of them would have to grow up together, knowing that their full-blooded relationship was divided amongst the three of them. My boys would have to share a mother with their new half-sister, while she'd have two brothers that were completely related to her.<br><br>I felt conflicted about it. Part of me wanted to keep the family together, stay with my wife, adopt the child, and raise it as my own. After all, a family doesn't have to be related by blood in order to be a family. And I was ready to accept the baby into my life and raise it as my own daughter.<br><br>But I just can't stay married to my wife. The trust is broken. I can't share a bed with someone who cheats on me. I can't look at this baby and not think about her infidelity. I can't look at her and not wonder about where her loyalties lie. In short, I have to divorce her.<br><br>I know this divorce is going to be like a punch to the gut for our two boys. They have no idea that their parents are having problems, and they just discovered they had a new baby sister. They think that we're a happy family, and I know that this news is going to knock the wind out of them. <br><br>Their little hearts are going to break into a million different pieces. They'll lose not only their mother and father, but their full-blooded relationship with each other. They'll now have to share a mother with a new sister that they can't relate to, and a baby sister will have to grow up knowing that she effectively destroyed her family.<br><br>And I'm not sure if they'll be able to get over that. Part of me is afraid that they'll grow up resenting their new sister. And I can't blame them for that. I'm mad at her for exactly the same reason. And I'm worried that they'll never be able to move past that animosity. <br><br>So I need some advice. How do I prevent my two boys from growing up resenting their half-sister?<br><br>&#x200B;<br><br>**EDIT:**<br><br>Wow, this blew up faster than I thought it would. Unfortunately, I have a lot on my plate today, so I can't answer all of your questions. I'll try to answer the common ones I've seen so far, though.<br><br>**1. Did I think that my wife was cheating on me?**<br><br>No, I did not think that my wife was cheating. And believe me, I've wracked my brain for signals that I missed, but there were none. She never gave me any reason to be suspicious of her in the past, and she never gave me reason to be suspicious this time. I thought we had a happy marriage, and I still have no idea why she decided to cheat. Like I said above, she told me that it was an emotional affair that only got physical after a couple of months, but I have no way of verifying that. It's not important to me at this point. She cheated, and that's all that matters. <br><br>**2. How old are my boys?**<br><br>Well, one's five years old, and the other is two. They're too young to really understand what's happening, and they have no idea why mommy's crying so much these days. I've been trying to shield them from the worst of it, but just trying to keep things normal for them has been difficult. They miss their mother, and I miss her too.<br><br>**3. Do I know (or care) who the father is?**<br><br>I have no idea, and I don't really care. I know that the mother told me it was one of her co-workers, but beyond that, I'm not bothered. There's nothing I can do about it at this point, and I can't change the past. If I ever learned who the baby's father is, I would never tell my boys. They have no idea that their new baby sister is actually their half-sister, and they never will (if I have anything to say about it, at least.) <br><br>**4. Am I going to try to get sole custody?**<br><br>Absolutely not. My wife loves our sons (and baby daughter) more than life itself. And one of the few things that we agree on is that the kids should grow up with parents who both love them. We're going to try for joint custody, and we both want to be involved in their lives going forward. We both know that having parents who love and care for you is important, and we want to provide just that for them. As long as she's abusive towards me, I can't live in the same house as her. But she's an amazing mother, and our boys are better off with her than they are without her. <br><br>Thank you to everyone who has given me advice. I really appreciate it, and I'll try to implement it going forward.