Boyfriend won’t let me meet his kids

Hey ladies,

Need opinions on this topic because I don’t have kids of my own. I’ve been dating my boyfriend for almost two years. I still have not been able to meet his children. We have a little bit of an age difference between us as well. His kids live in another state so he has to take a plane ride to see them. He stays at the mother’s house every time he goes to see them. I’m starting to feel like I’m purposely being avoided and I’m not sure what the reason is. I’ve been asking for awhile to be more involved and it seems like it’s a lot of excuses.

Ladies please share opinions.