He lets out this obnoxious loud burp and of course giggles because burps are the funniest noise when you're a 3 year old boy. Who am I kidding, guys of all ages still think they are the funniest noise along with farts.
I, being the polite lady in the house, try to instill some manners with the boys, so after he burped I waited for him to say excuse me. It was apparent to me that the politeness I expected was going to need some prompting so I said to him, "Luke, what do you say?"
He responds, "Thank you!"
We've got some work to do in the appropriate response of the manners department, but at least we're on the right track.