Meaning of sorry!

I know I know..I've already done 2 posts (this and this) on trying to make Betu understand the meaning of sorry. But I think I've reached the finale and he has actually understood the meaning. This time I told him that when he says sorry it means he will not do it again. And as usual he nodded his head in affirmation. This was about 5-6 days ago.

And yesterday when we three were having dinner at the table, DH dropped some curry on the table cover while serving him some. So Betu immediately goes "Say sorry!" Fine.. DH said so. But that was not it. Betu says "Sorry ka matlab hota hai dubara nahi karunga. Aap bolo aise!" DH had a little laugh and when he repeated what Betu had told him to, Betu goes "Good boy!" just the way I say to him.