Exploring aspects of your personality is an inherently self indulgent thing to do. That is the whole point! When you express masculine qualities you are self indulging your male side. So what? Is it a crime to express yourself? As for addiction, you cannot become addicted to displaying the real you. Self-expression is not addictive. There are addictive issues about femininity such as the fashionable clothing but this is an issue all GGs themselves have to deal with as well. It is not an argument that can be used to stop self-expression.
This is a false discussion. Lets read between the lines, The issue here is your wife believes in and wants the artificial social divide between masculine and feminine. This makes her happy and content when you behave the way society programmed you to behave. Her expectations are met and she gets peer approval. By crossdressing you break down the artificial barrier and become a more whole, complete person hopefully more knowledgeable, more empathic, more understanding and of course happier. You want to step outside the box while she wants to remain firmly locked inside.
No spouse should demand that their happiness is more important than their spouses. How can you be happy at the expense of your partner's misery? The only solution is to either learn and grow together as a couple, or agree to a don't ask don't tell policy. Otherwise the relationship is heading for the rocks.
