She pranked me.

Today... my sister...
She... she left a message for my friend(FROM MY PHONE) saying "I'm changing my mind. My dad wants me to choose natural sciences or technology. But I want to choose hairdressing too ;__;(program for high school) without me knowing =  = so.. when I went to school today my friend came up to me in the morning with a big smile on her face saying:
"Heyy, I'm so sorry I couldn't reply to your message. But what made you change your mind?!? I mean, are you serious?? :D I'm so so happy"
I didn't know what she was talking about... =  = and I was like:
"what do you mean?"
so she got a bit hurt and said:
"what? so you're telling me you can't remember what you sent to me???"
so when I looked at my phone again I saw a message from her saying:
"OMG!! We can open up a barber shop together in the future!!! and we'll work together! It will be so much funn! <3<3<3 Let's talk about this tomorrow"
OK. So. I started sweating and my face got hot... and I saw that message that "I" sent to her... and remembered that I lent my sister MY phone yesterday so.. she must've sent that message to my friend, to mess with me.. e_e and then my friend said:
"Or... was it all just a joke?" and her smile started to fade a bit and.. omg, she was so sad at that moment so.. I lied to her ;A; I said:
"of course not! I want to.. really. I don't know.... there's so many things I'm interested in right now.. I just don't know what to choose... and yeah. I've gained interest in being a hair stylist too. but my dad wouldn't let me, you know that"
Oh.. I felt so bad ;__; I was so so mad at my sister. WAH, I'm so lucky that I'm unsure of what I want to become in the future.. so.. she knows about me changing my mind a lot about what to choose............... but still.. because of what happened that moment, I even thought of changing my future for her... IT WAS TERRIFYING! SO SO FREAKIN TERRIFYING ;__;

It's okay about pranking me but.. playing with feelings is a "NO". I mean.. my friend was so happy about it.. ugh... I just don't like it when someone jokes about something that will you happy(sounds weird). Because it's like TORTURE. It's like joking about loving someone, who actually loves you..
I don't know... This is just my personal opinion.