Ellie kidnapped you, she desperately needed company and all she could find was a small autistic girl, you. The first night you managed to get some sleep, she made you sleep in the same bed as hers, well, not a bed, just some crappy, gross mattress she found and you'd rather sleep on dirt Ellie might have taken advantage of you during the night, you just looked so cute, she couldn't help herself. She's been alone, touch starved for so long, she needed this, you owed her that.