Here is my copy-and-paste ABA speech ---it isn't going to apply to you EXACTLY, because your bird's motivations are impossible to know for sure without charting , but the principles are the same for any animal (humans included):
My main point in posting this is for the details on ABA- I am NOT saying your situation is the same at all, but it give you an idea of how ABA works.
"First--- mitigate hormonal influences and get rid of triggers--In the short-term, things that impact behavior outside of you or the bird are sometimes called "setting events" :
1. remove all snuggle huts, tents, caves and hammocks from his cage and don't let him hang out in bedding, under cloths, in boxes etc.
2. Pet on the head and neck only.
3. 10 hours of sleep on a schedule each night.
4. Make sure he is getting plenty of activity and enrichment/ things to do
***This is normal---all birds go threw a rough patch at puberty BUT with appropriate responses, you can adjust to these changes****
From there, I would recommend Applied Behavior Analysis (ABA). Start by making what they call an ABC chart (antecedent= what happens right before the bird's behavior, behavior=what the bird does, c= consequence =what happens right after the behavior (good or bad---consequence is just the RESULT and it doesn't mean consequence in the same way that we sometimes think of a consequence).
In the scenario you gave above:
Antecedent= Son laughed while you were playing with him and bird was on you.
behavior= bird flew off and bit son on lip.....You didn't say what happened next, but that would be the consequence.
consequence= WHATEVER YOU AND YOUR SON DID=== did he cry? Did you yell? Did your son leave the room? Did you put the bird back on the cage? Did you stop playing Monopoly? All of these things are really important because all behaviors serves a purpose. People and animals only do things because we are rewarded in some conscious or subconscious way by the results of the behavior. This is called the "function" of a behavior (the reason we do it). A behavior can have more than one function, but all behaviors fall into 1 of 4 categories:
1. Escape (to get out of a location, get away from a person, avoid a task/activity etc)
2. Attention (to get attention from humans or animals which may include eye contact, yelling, laughter, increased proximity, scolding etc)
3.Tangibles- to obtain a physical item---e.g., a kid throwing a fit to get candy at the grocery store or hitting another kid to take their toy. Heck---working for a paycheck also falls into this realm.
4. Sensory= eating when hungry (to stop the hunger), taking a pill for a headache, scratching your skin because it itches, crying as a response to legitimate pain.
I would say that this behavior, while rooted in a sudden change in hormones/ drive, can be shaped if you start to understand how everyone's reactions are likely feeding into it.
By charting ABC's of a behavior, you start to see a pattern. When you look at the "c" column (consequences) you will find a general pattern. Without knowing more about this pattern of behavior and consequences (e.g., charting it) I cannot say with certainty what the function/reason is, but just based on what you said and based on my experiences, I am going to guess that after you do the charting, you will probably notice that the majority of the "consequences" will be linked to the theme/"function" of attention ---but when you look at the chart, you will want to ask yourself, is this consequence creating an opportunity for attention, escape, tangibles or sensory. You may have a combination, but you are looking for the once you see most frequently across the board in relation to this behavior.
This is how you determine the function (reason for doing) a behavior. When you know the function, you can then manipulate the behavior by A) NOT gratifying/rewarding the behavior with consequences that serve the function and B) providing more appropriate ways for the function of that behavior to be met without doing it in an inappropriate way. These are socially acceptable alternatives to the undesirable location--- they allow the same function to be met/gratified, but in a more appropriate way.
From the sounds of it, your bird is likely motivated by 1. primarily attention from you and 2. Escape/avoidance of your son (because he is an attention-blocker/associated with lack of attention from you).--I AM JUST GUESSING--- IF I AM WRONG ABOUT ATTENTION BEING THE FUNCTION THEN YOU WILL NEED TO DO A DIFFERENT INTERVENTION---
I can't say for sure without knowing how you react when this stuff happens, but if he is like most 7 year-olds, here's what I imagine:
Playing game with you (attention is on game and kid) , Kid laughs, bird bites.
Kid screams, you stop paying attention to the game , you yell/scold/react while looking at bird-- if this happens, so far, the bird has learned that biting gets attention from you and your kid (if what happens is anything like what I just described)--if your kid leaves, then your bird no longer sees you giving him that attention and all is right in the world again (the "threat" has been removed). He wants your attention because he is a flock creature, but also because he is reaching sexual maturity and likely views you as a mate and in the wild, conures do not share mates. Your kid is a potential threat as long as you are a sexual object. This doesn't mean withdrawing all attention from your bird, but it does mean that you will have to be EXTRA mindful about how you interact with him in order to set the bird up for success (before the behavior occurs and in situations where the behavior is likely to occur).
In an attention seeking behavior, the bigger your reaction, the more you are rewarding the bird. In this case, 2 people reacting with urgency could be quite gratifying!
Assuming the bird really wants attention from you, instead of making a big thing of it, my suggestion would be to firmly say No (NOT loudly, one time) and use something like a time-out cage to isolate the bird immediately following the bite. If you are the object of the bird's attention seeking then you need to accomplish this as quickly as possible with as little eye-contact/reaction as possible. This will only work if you are absolutely certain that your bird is biting for attention--- by doing a short time-out away from you and your son, his attention seeking behavior cannot be reinforced.
At the same time, after a short time-out, you need to show him positive ways that he can get attention from you while your son is around WITHOUT biting. This is that socially acceptable equivalent I discussed earlier-- if he bites for attention, maybe you teach him to ring a bell for attention, say a word word for attention, take a treat for attention etc. Something that gets him the same type of reward without upsetting the household.
Because this involves a kid, it IS more complicated though because it's going to be really hard for your son to control his reactions. If he cannot control his reactions, then you need to consider avoiding situations in which things like this can occur, because if you are trying to stick with the "ignoring" program, but he keeps reacting, then you will likely make the behavior even worse...so it's important to be as consistent as possible once you start an intervention.
I would definitely try to pair your son with positives for the bird. It is likely that you pay attention to your child more than the bird when he is around, and that is no fun for the bird. Try to make a consious effort of giving your bird MORE attention (for positives) when your son is around and pair him with as many positives as possible. In an attention seeker, attention will always be the most important reward, but you can tack on other incentives too (like a favorite treat whenever he is with you and your son). The thing is, the treat MUST be secondary to the main reward (attention ). While it can help strengthen positive associations, an attention-seeker's behavior is never going to be impacted by food alone (unless getting that food is accompanied by the attention it desires)."
BECAUSE IT WAS REINFORCED and the benefits of doing these behaviors outweigh the consequences of not doing them. I say all of this because I feel like sometimes people get offended when they first read about ABA, but it's just a way of looking at the world .. People who don't like ABA still run around reinforcing behaviors (good and bad ones) but it's the mindset that is lacking, so they are kind of flying blind. 
