My sister keeps punishing me. Does she have the right to? ?

I'm 17 (almost 18) & my sister (21) let me & 2 girls & a guy hang out at her apt a few times. Last time she went out for a while & we started a strip poker game after some beers. She came back a lot sooner than expected & the guy had his shirt off, & us girls were basically in bras & panties. She was angry but somewhat understanding too (I thot). She sent the others home & said she could tell mom & dad or she could punish me since it was her apt. She said since I was risking being naked, I should go without clothes on this & future visits until I learned my lesson. I also had to do whatever chores she wanted for at least a month. She threatened to use her sorority paddle on me but thankfully never did. She did smack my fanny with her hand a few times. Once or twice a week I have to go there & do her bidding naked. Housework, scrubbing floors, ironing,etc. She usually hazes me too, like crawling, bowing down,kissing her feet, sitting on ice, jumping jacks,smacks on the , etc. It's been 5 weeks but she says time isn't up yet. Last time I asked, she gave me a formal . I'm too deep to rat on her now, but isn't she going overboard with power here?? I really did learn a lesson from this & more punishment won't do any good.