The strangest family ever...

Ta
My husband has yet to tell his sisters that we're expecting our first child (currently 17w). We're not very close to them so I really don't care when he tells them. My husband left home at 18 for university and has been on his own ever since.
Well, my really good friend just had her first child and we want to fly out early November to see her (she lives on the other side of the country). His sisters live in the area so he suggested, let's go tell them in person then. I agreed as it would have been really convenient. Plus it would have been funny to see their eyes pop out at my belly (23w by then) as they have no clue 😂
We're visiting my in-laws (they know and are excited) and my husband tells his mom our plans. She goes,"But no one will be there! They'll be in Hawaii and so will we. Didn't they tell you?" 
He has no idea what she's talking about. Turns out that his sisters, along with their spouses & kids, will be taking everyone to Hawaii in November. Including his parents = everyone on his side of the family will be going and not only did they not invite my husband & I, they didn't even tell him 😳 The poor man didn't know how to respond to his mom. Meanwhile, I'm trying to quietly extract myself from the room due to this family weirdness and all I can think is how not surprised I am 😂 His whole family is weird but his sisters are very strange so like I want to go on a family vacation with them but I felt really bad for my husband.