Dealing With Playful Biting/chewing

I'm looking for some advice about how to deal with some behaviour. I have two 9 week old budgies who I hand reared from three weeks of age. At the moment they are chewing EVERYTHING so I assume it's a normal behaviour. My problem is they are also chewing me which is now starting to hurt badly enough that I can't ignore it. This is not a fear based thing as they are happy being handled (and one who is older and spent a week with me without a sibling and is quite affectionate). It's mostly happening while they are playing/free flying about the room. I am also trying to give them as much positive attention as I can when they are not chewing on me but it's gotten to the point that we are having more negative interactions that positive (as I have to shoo them away).

Really hoping for some advice because I love these guys but I have work to do, and can't keep spending half my day shooing them away because they are hurting me!