It's not discrimination, it's your boss organising his team in the way he wants. The common sense unwritten contract is that you do what your boss asks, and if you keep working hard enough and smart enough then one day you might be a boss. But you can't give back-chat and expect to be well thought of. It's only against the law if you are not allowed reasonable breaks in proportion to the hours you work or are orederd to do a task that is dangerous or illegal. If you want to build up a relationship with your boss where you can have discussions about who does what and when you must work at this relationship as you would at any other.