Do you teach and expect your kids to thank you/spouse/partner after every meal or snack?

I ask because the 8 year old my husband mentors never shows a sign of respect and courtesy like "hello when he visits us, please and or thank you" after he eats. We are originally not Americans so it was more of a surprise to us when he would finish his meal and walk to the living room to watch TV without a word to us sitting at the table.

So guys what do y'all think? Is it a cultural thing or a parenting oversight?

And how would you handle this without making his mother feel like she's not raising a grateful kid.