This sounds so frustrating. As a parent, what can you do? I hope that once Casey matures and grows more comfortable in his own skin, he's not so trigger-sensitive when Cuy tries to share his joy. It's also frustrating for you and Cuy to tiptoe around Casey. Has it always been like this?

My two kids are younger (still in HS and girls) and I'm hopeful they continue to be close. It sounds like it's just luck of the draw when it comes to siblings!