My 2 year old pre-teen

So lastnight at dinnertime, I'm preforming my usual routine of telling Alex to finish his dinner so that he can have something for dessert. He'll normally eat most of it, but some veggies he won't touch. My biggest obstacle is getting him to TASTE things. He claims to think they're "disgusting" before he's ever tasted them. So I'm at the table begging, "Take one bite of your salad and you can have a popscicle...come on, you can do it, it's just one bite..." and this little booger looks at me and ROLLS HIS EYES!!!!! I had to leave the room to laugh it was so funny. He definitely does not have the rolling of the eyes perfected quite yet, he looks more like he's dying than anything. The eyes get stuck about midway around and just kind of hang there looking up, while he puckers his lips so as not to laugh. So, I leave the room giggle a bit and then come back in as "well behaved mommy" with my straight face put back determined not to laugh. Sure enough the booger does it again!! I try to get Mark and Ashley's attention, because they HAVE to see this, but the moment they look, Alex plays dumb. He acts like he was doing nothing and refuses to "show daddy what he just did". He looks at me like I'm crazy, shrugs his shoulders and Mark continues to clean the kitchen. As soon as Mark walks away, he does it yet AGAIN! I try to get him to do it for Mark several times after that, but he adamantly refused. What am I going to do with this boy!!??