Don't want to be around my stepbrothers

So a little background info. My husband and I are mid 20's, just had a baby 6 months ago. My parents divorced and my dad remarried when I was young. My stepmom has 3 boys, all around the same age as me and I spent half my time growing up with them. Well now the boys are grown and they just don't seem like good people. We don't like being around them because of the rude remarks and attitudes. They never said congrats on our pregnancy and never reached out or said sorry when my mom passed away. I also think they stole from me when my mom passed and her house sat vacant for a little while till I could clean it out and sell it. My mother's wedding ring and a necklace I gave her were missing. They knew the house was empty, but I have no proof that they did steal.

Now on to the problem. I invited my step mom and dad to our Halloween party. A couple days later she asked if the boys could come. I said no. My dad texted me the next day saying she was really upset and crying. And that we need to talk about it. And that now they aren't coming to the party.

So now we have to have a very sensitive and awkward conversation with my stepmom and dad. Would you tell them that you think the boys stole things? Do you think I'm being harsh? Do you think they deserve a chance?

We just feel like family should be people who love and respect you and care about you. Not just because my dad married your mom