We have zero tolerance for this, as it's really disrespectful. They are absolutely testing and seeking boundaries - and I'll definitely give them those boundaries! It is a CONSTANT process but if you let them do this they will think they can run ALL over you. My two do this ALL the time. I ask once, then ask, "X, did you hear me talking to you?" And then if no response, end whatever activity seems to be distracting them (turn off TV, take toy gently away, etc), until they answer - if they escalate (hit, won't let go of toy, scream when TV goes off, still won't answer, etc) then they go straight to their room. I tell them when they can be pleasant and respectful toward Mommy/Daddy they can come back. Usually it's a quick round trip up and then back down the stairs with an improved attitude as they hate being banished from the family
. If his room is too much fun, I'd change that - I did have to remove all of their toys and books from their room - and most from the rest of the house - for a while to make that a less appealing option! Our garage became an enormous toy jail at the height of their naughtiness (or so I thought LOL), because we were taking away so many toys and privileges - we were down to almost nothing in the house when they finally cried uncle and started getting (a little bit) with the program. So what if I have to park outside, right?!
Seriously, I would have zero tolerance for this. Asking a second time is totally reasonable if they're absorbed in an activity (adults do that too after all, it takes a second to realize that someone is talking to you and to concentrate on the question, if you're really into something), but after that I'd calmly send him to his room until he can be respectful, and just smile and say when he's ready to do x, y, z, he can come back out. If he won't go (like mine for the first month or so of that penalty), pick him up and put him there. Just stay calm and smile and reinforce when HE can act that way he can rejoin you.
GL!!! Honestly, preschoolers are a real PITA sometimes! They're lucky they're sooooo danged cute. Hugs,