If he is jumping back n forth between the two of you he is getting bonded
The pouch protectiveness can be worked on. My male was extremely pouch protective, he just needed us to make a few different changes in how we were using the bonding pouches.
Most bonding pouches are deep and close with a zipper, so the glider can't see, which makes him scared. Lunging, crabbing, slapping, biting are really their only defense against anyone in their "personal" space. They do those things to keep you at a distance. Pouch protectiveness is usually fear based not aggressive based.
I found regular bonding pouches to be more of a pain in the arse when bonding with Simon. I had recently posted this to someone else so insert 'him' where the her's and she's are lol I'm to lazy to go through the whole post and fix them.
So I started using a single layer pouch that was nice and wide, that I could easily role down a couple of times. It will almost be boat shaped. For the first few days just have the pouch with her in it in your lap. She's probably going to lunge and crab still, You can also put a small fleece square over her so feels a little less exposed for the first few days. She will still be able to lift her head up and see whats going on. That's the big thing with I found with pouch protectiveness, they need to SEE and in a deep zipped up pouch they can't see what is scaring them. When you make a noise she will crab and look to see what made the noise... When you move, she will crab then look to see whats going on...It doesn't take to long for them to figure out all those scary things aren't going to hurt them.
Once you have her in the pouch I usually keep the pouch in my lap, and offer a treat. When you offer her a treat don't try to put it right up to her face, give her an inch or two so she has to stretch her neck out to take it, This shows her you are trying to respect "her space" and makes her meet you half way. The first few times or even first couple of days she may try to swat the treat out of your fingers, that's fine just don't retract your hand or react to her fast snatch of the treat. She will start to see that you aren't going to hurt her and will start taking the treat nicer, by you not jerking your hand back your also not scaring her with your fast reaction. When she starts taking the treats nicer you can start offering them closer to her face, just proceed slowly each day a little closer until you can put the treat right up to her nose.
Consistency is a huge thing for pouch protective gliders. Get on a schedule, everyday at the same time get them out of the cage, everyday at the same time do treat time. Even a pouch protective glider will get used to YOUR routine and come to expect to be taken out of the cage at 11 am or whenever you get them out for bonding time, they will expect treat time at 11:15 am or when ever you start offering treats. This will help the pouch protective to know whats happening and she will not be as surprised that you are randomly getting her out of the cage and out of her sleeping pouch etc...
So part of the reason for the open pouch is so they can easily lift there head and See whats happening. The other reason for it is so YOU aren't reaching blindly into a dark pouch and getting bitten. With the open pouch YOU can also see where she is, and what she is reacting to by crabbing/lunging
One important thing to understand here is Lunging, slapping, biting are a gliders only real defense. The objective is to scare away predators, keeping predators out of the gliders personal space. You my friend are considered to be just that, a predator.
Now, once she is at the point where she is taking treats a little nicer, and not crabbing as much in the pouch at every little thing... Then you can proceed with trying to pet her in the pouch.
When she has her head tucked/sleeping, fold your fingers down and pet her back with just your knuckles.
1. A bite to the knuckles doesn't hurt as much as bites on finger tips
2. A closed hand looks less like a claw coming at them and is much less threatening
If she crabs thats just fine let her crab, If she raises her and looks at your hand just be calm stop petting and leave your hand right where it is!! lunging is pointless right here because you have already broken her personal space invisible barrier, your hand is already there do NOT RETRACT IT. She will most likely tuck her head back down or try to get more into the corner of the pouch, just let her. When she settles down again start petting with your knuckles again. Once she gets more comfortable being touched on her back you can work your way up to her head. Once she is ok with head being petted then you can start using your fingertips instead of your knuckles.
Once she's ok with all this.... then you can cup her with your hand, at this point she shouldn't be crabbing or lifting her head as much to see what your up to. You can pet her while your "holding" .
Now at this stage, I started unrolling the pouch by one turn so gradually the pouch gets deeper. Leave at one unroll for a few days or a week depending on her behavior. Then do another unroll and so on until the pouch isn't rolled down at all. You can also use the regular bonding to help her get used to the zipper sound, just open and close it near her every now n then so she gets used to the sound so when you put her back into that bonding bag she is already used to the new zipper sound and won't crab over you opening and closing the pouch.
Sorry this is so long, but details are sort of important when working with pouch protective gliders. Just remember there is no time frame for this, only proceed to the next step when you feel the glider is ready, don't rush it!!
All of these methods really helped Simon. I can offer him any pouch now with no fussing at all, I can have my hand and half my arm in there with him now.
Take your time, get on a routine, and be confident when you interact with her. only move on to the next step when you feel she is ready for it. This is not an overnight fix, and progress is very exciting when it happens even if it's a little thing lol Open pouch like this outside of the cage should always be supervised (obviously lol )