This is exactly the kind of thing you're not meant to do with a company you don't wholly own (and to some extent with any limited liability company). Part of the deal is that as an executive or majority shareholder the company is not an extension of yourself, it's a seperate entity and when making decisions about it you are meant to act in the interests of that company. This is sadly not well enforced, but it is the kind of thing where shareholders can and will take action.

(Musk has been heavily criticised for pulling these kinds of shenanigans between Tesla, SpaceX, and X, but it seems like there are not enough shareholders willing to take him to task for it)