Are my feelings valid ?

Ok so I know what I’m gonna say is going to sound bad, but I just don’t know how to feel and if my feelings are even valid. When I met my boyfriend he had 2 sons. Then we had our son in 2016 and our daughter in 2018 and I’m currently pregnant with our second son. I have caught him cheating multiple times and I know it’s stupid of me to stay but I did. One of the girls he cheated with just had a baby last June and claims it’s his, then another girl came out of no where 2 years ago claiming to have a 3 year old daughter that was his 🤦🏻‍♀️. And I’m struggling a lot to accept this. I love and accept his 2 sons he had before me completely. BUT I cannot accept these other 2 kids I just don’t wanna hear anything about them nor do I wanna be around them or have them around my kids. Now I understand these are his kids but it hurts me and angers me every time I think about it or he brings them up. And I don’t know how to tell him how I feel. I know the smartest decision would be if I can’t accept his kids to leave him altogether but it’s so hard to think about doing that especially because I’m currently pregnant with our child. It’s just such a stressful situation and I feel like my feelings are wrong.