Mom allows teenager to run the house

I absolutely love my family. Not having been a parent and only having cared for my god children this was a learning experience. The trouble I am having with finding balance is that our 15 year old often takes this very arrogant attitude that he runs the house and everyone should do as he says right away and without question.

His biological father was, as I have been told by everyone, a master manipulator and he used silence and pouting as punishment. Sadly, my step son has learned that.

His mom is a strong woman but she very rarely enforces anything with him. For example, the classic issue with cleaning of the room. She has been after him for just over 3 months and not only is it not clean but this 15 year old has now spread his things to several other rooms of the house.

He can often be a very thoughtful child. He is very intelligent, quite funny, and very creative. He does, however, constantly back talk and raise a voice to his mom, his brother and I. He does not take into account the thoughts and feelings of others; his need in the moment is all that counts. He has often manipulated his mother, who works night shift, into going without sleep to ride him to school just because he does not want to wake up 20 minutes earlier to ride with a friend.

Any advice how to ignore and not be repulsed by the disrespect of his mom, how to not argue or complain with him but how to encourage a healthier behavior. Also, how can I convince my spouse to consider using a little discipline. He disobeys her frequently but since he isn't into bad behavior such as drugs and alcohol and such, she almost never takes away a single creature comfort.