My Best Friend (Markiplier X Reader)

Y/n is a 19 year old girl who lives alone in apartment. But she's not so alone as you would think. She has a very close best friend name Mark (Markiplier). Mark and Y/n are un separable and they do everything together.
Recently Mark became very different and
Y/n meets a boy named Alex. And they slowly fall for eachother. But Alex isn't who he seems to be.
Mark starts warning Y/n about Alex. But she doesn't know.
Mark then tells Y/n how he feels Hoping she would understand. Then she gets caught in a loop of a mess and nightmare.