Our middle son, age 4.5, has recently been very big into making superfluous demands. I suspect he is feeling insecure (the littlest is just now 1 and seems suddenly less like a baby and more like competition, I'm sure) and needing reassurance that we love and value him. I am doing all I can to meet that need (including trying to convince DH that that need a) exists, and b) is causing the unwelcome behaviors.)
Until he finds his place and reassurance, how does one handle the troublesome behaviors? Here they are- the first two deal with "no."
1) Making "superfluous demands"- requesting multiple glasses for one beverage at dinner is a good example. This sort of demand is almost always clearly above and beyond the more typical specific child-like needs that small children think are crucial, and usually are made when it is most inconvenient for the parent to comply (in the example above, after everyone has been served, grace has been said, and all are finally sitting at the table.) On Easter Sunday, he said he would not go to church unless I made the sun less bright. That sort of thing. It's like he wants to hear us say no so that he has a reason to have a tantrum. If you comply with a demand, he will make another until he gets a "no."
2) He has also begun to have more instances of blatant disregard for instructions. "L, don't throw rocks." L, smiling, throws rocks. L, don't run out of the backyard; it's not [L runs out of backyard]...SAFE!!!" "L, you just threw a hard block at your brother. We do not throw hard things in the house, and we don't throw anything directly at someone's head." He picks up a hard-back book, throws it as his brother's head.
3) Destroying small items around the house when unobserved. Yes, the simple solution is to observe him more, and I am trying to do that, but the 1 year old is almost able to run already and there are limits to my superpowers. He will not admit to the destruction. The deceit worries me more than the actual damage (though he most recently broke a sweet $10 wooden top that the Easter bunny brought him by snapping the spindle off.)
I am a "yes" parent. I say yes whenever I can. But there are some times that I can't say yes. And, more to the point, I need him to understand that I am willing to show him I love him in other ways than leaning over backwards to comply with his requests. If doing so felt like it would help him, I would do it- but as I've said, it seems he is just experimenting, seeing how many things he can ask for before he is told "no."