I was the female version of your stepson at that age (but never got accused of smelling, did have rather stringy/oily hair though :-) let me see if I can remember back to that painful time with my stepmother. She tried to stuff a washcloth down my throat one time because I was lying about bathing. It's not about the "obvious".

I did not see all the things my stepmother did for me, the cooking, cleaning, and otherwise "providing" because I was too shut down and introspective. My mother died when I was 3, I do not remember her. It sounds very confusing for your stepson having his mother and you, maybe unconsciously wishing for the "normal" father/mother household. He's an only child, too? There is nothing to get any focus off of him? If you do not have anything in common, don't "get" him (not your fault!) you all could be missing each other in trying to communicate, all he hears/feels is complaints and people trying to control him and make him something they think is right without helping him find what he might like to explore for himself and that it is safe emotionally to do so?

It is hard to put ourselves in someone else's position, especially if it is not a natural position for us? Too, he is a child, does not have the words or wherewithal to understand himself, has no way to communicate except the very basic, resisting/opposing. He has no tools or means of getting any. Has not learned anything, experienced anything firsthand.

I would see if you could maybe get an older teenager tutor for him? That helped me a little (though I fought it, felt very insulted that it was suggested that I needed it), I did not do my homework and was doing poorly in French (among others but French was not something I could fake) and having someone there who did not pressure, was patient and closer to my age and situation, etc. I opened up a little bit and at least did better in French :-) I do not know if that would work with boys though?

I have three brothers and my oldest had similar problems with our stepmother. I think your stepson needs a wider environment? Are there any YMCA/Boys and Girls club activities, something/anything at all that he likes that could put him in other people's company so maybe he would like to conform better to some things (everyone showering after sports, for example)?

I know now, if I could do it all over again I would myself go out of my room and try to talk to my stepmother (she and I did not communicate well), ask her questions about herself and maybe try to share some of my difficulties/feelings. Maybe spending more time with him while doing day-to-day things, not do "for" him but "with" him?