Older sister being hypocritical when it comes to my boyfriend

So I'm 14 and my older sister is 17. We both have boyfriends and we live with our dad who is 10x stricter with me than with her even though I'm not as annoying and mouthy as her. I posted an old video on my snapchat and it was just of me grinding on my bf while he held my ass. My sister texted me and told me to take it down or she'd show dad. I took it down but I told her that she was a hypocrite. I hear some her phone conversations with her boyfriend and they're very sexual so I threatened to tell dad too. She said he already knows and I said thats not fair. I told my sister that I feel like she doesn't like me because she's always down my throat and bothering me. She told me that she was just looking out for me because people can repost stuff everywhere. I told her well let me worry about that if it happens and stop always telling me what to do because you're not my parent. She said alright sorry and I said whatever. She thinks she's the boss of me because she's older and that's literally not how being a sibling works.

Note: Okay for all of you saying a private convo is different they aren't just talking on the phone they've had sex before

Also it wasnt porn we were both fully clothed and it was just dancing to a song?!!!!