Why Does Brother Abandon Mother on the High Holidays?

Conversations with my mom....

Mom: So I guess Jimmie won't be spending the holidays with us.
Me: Huh? Why not!?
Mom: He'll probably be with Cara's family .....
Me: Really? No! Maybe for like, dessert...
Mom: Well he spent all of Rosha Shana and Yom Kippor with them!
Me: Who cares? You wanted him to spend them with you?
Mom: I'm just saying they invited him and he went to her house for the Jewish holidays!
Me: But we're not Jewish. They are.
Mom: I'm just saying Helen.