Slenderman had taken you back to the mansion after finding you out on your own in the forest and you had lived in that mansion ever since with little to no outside access. You were 17 years old and you were an age regressor. No one in the mansion really understood what the whole age regression meant, no one but Toby. He had Tourettes and had scars along his cheeks that would show the inside of his mouth. Toby had Tourettes which would cause him to involuntarily make sound, say random words, make certain actions such as biting the inside of his mouth or hitting himself. You were one of the few people who thought his Tourettes weren't weird or scary.
Slenderman would often just leave you with Toby since he was the only one who understood how to look after you when you were in your little headspace. He bought you basically everything you could need or want when you were regressed and he would basically be your caregiver.