My mom's boyfriend yells at me for the littlest things and makes me cry. How can I tell my mom the whole truth?

My mom's cruel boyfriend yells at me for the simplest things, like if I wear red or black eyeliner to go hang out with my boyfriend and his sister, a boy I'll call Ilia* and a girl I'll call Tatiyana*. They both think the Gork(a strain of punk subculture) and Lolita (a Russian alternative fashion movement) looks are nice. If I go with the Gork look and wear red eyeliner, which my mom is cool with, he insults me with stuff like, "You look like a tramp" and "Ilia* and Tatiyana* are both Communists", and I end up crying. Ilia's mom, a woman I'll call Lucy*, likes the Gork and Lolita looks and could really care less about my looks. I secretly tell Lucy*, Ilia*, and Tatiyana* what my mom's boyfriend does to make me feel bad about myself and I get responses from them like, "Don't listen to him." , "That's not good." , and "He's a real a$$hole". My mom's boyfriend always insults me when my mom is on a business trip or not around to call him out. When he insults me, he gets violent and yells like a tyrranical dictator. When my mom, dad, aunt, uncle, and the rest of my relatives want me to know I'm wearing too muck makeup or don't like what I'm wearing, they say something silly or say ,"Can you please...?" in a polite voice to express so, versus hurling cruel insults at my cousins, my sister, and me. After my mom's boyfriend gets the mean yelling over with, I end up venting to Ilia* ,Tatiyana*, or Lucy* about the situation. Ilia* and Tatiyana* end up beyond pissed, saying stuff like, " Your mom's boyfriend is not your real dad." and "Your mom should kick him out. End of discussion". When I tell Lucy* about it, she says stuff like, "It's gonna be over before you know it, kid." and "I was a teenager too, so I know exactly what it feels like to go through your situation" and I feel better about it. When I try to tell my mom about it, he turns it into something totally untrue by making stuff up. Of course, my mom believes him an punishes me. How can I tell my mom the whole truth wihtout being mean?