Clear mating behavior, time to take some action
-Limit daylight hours. Be sure the bird has 100% DARK AND QUIET for at least 14 hours per day. You may need a second cage for sleeping to make this possible. Long days means spring means BABIES!
-Make sure the cage is in a bright place (no dim/nesty corners) Dim areas can stimulate breeding and nesting behaviors which means BABIES!
-Rearrange his cage and even the room he is in, or move him to a diffErent room. Safe and steady environments are signal to him that this room is great for raising BABIES! You want him to feel safe, just not feel like everything is steady and safe enough for BABIES!
-Limit fatty foods. If you are feeding an all seed or seed/pellet mix, it is time to change that. Research sprouting for your bird, it is easy and cheap, super healthy, and an easy switch from seeds. Diets high in fat are great for raising BABIES and your bird knows it!
-No mushy or warm foods, because that is what parrots feed their mates when they are getting ready for and raising BABIES!
-ABSOLUTELY NO snuggle huts, tents, nest boxes, and no letting the bird get into tight places like shoes, etc, because those are all great places to raise BABIES!
-DO NOT allow your bird to snuggle under your hand AT ALL. Allow him ONLY to step up and get head/neck scritches. No shoulders as those can be snuggled against your will. Do NOT put your hand over the bird's back unless there is a true emergency. Some birds cna handle touch without going nuts, yours is not one of them. Every time you touch him, or even almost touch him on his back it makes him want to MAKE BABIES!
-EVERY time your bird drops his (more likely her) butt or does any of the "nesty" things you describe, immediately put the bird back in the cage. You need to send the signal that you DONT WANT HIS BABIES!
-Limit food. Be sure your bird has enough to eat, but don't allow grazing. Feeding two "meals" a day and then removing the food is best here, because where there is an abundance of food, birds have enough food to feed BABIES!
-Make sure others in the home are handling the bird (You said you do that, which is good).
Birds are programmed to respond to signals in their surroundings, food, and mate and when the time is right, instinct tells them to MAKE BABIES! Guess what that means? When they cannot make babies, they get sexually frustrated, because they are being led on. Leading someone on sexually is mean no matter who you are or what species they are, so it is important to take steps to change the signals around your bird so that he doesnt think it is time to MAKE BABIES.
IMPORTANT NOTE!!
Some people think that thier pet wants to have babies, so they should get them a mate and let them do it. Please do not think this, it is a really bad idea. Raising birds that will make good pets AS ADULTS is a lot more involved than simply keeping the babies alive and tame long enough to sell them. People who breed their birds for this reason usually do not produce quality pets (even if the babies are sweet when they are little), and they are NOT "doing what's best for the bird" by letting them reproduce. I won't go into detail here about the thousands of dollars of vet care, fresh diet, large cages, hand feeding equipment, etc that goes into breeding, or the psychological and moral issues at play because your thread is not about breeding. It's just that after a long post about how your bird wants to have babies, I thought it was important to be clear that the best thing for your bird is to CHANGE THE SIGNALS SO HE DOESNT FEEL THE NEED TO HAVE BABIES.
Also, these suggestions are for birds exhibiting mating behaviors, not "must do's" for every pet bird.
