You're... An indulgence, he'll admit. No one has to know about this. If you don't behave like he wants you to, he'll just have all the more reason to get rid of you; he won't have an embarrassing secret to have then. But Hohenheim had a wife, humans have partners. He has his "children", you're what he'd be missing to complete the image.

But a human won't fit that image. So, he creates a homonculus. You, made to love him.

"I shouldn't be indulging like this." He muttered, leaned back in his makeshift throne. It was easier for him to have you stand besides him. Father isn't entirely aware of where your image came from, maybe just a collage of humans he's seen over the years.

Father lifts his hand, tentatively toying with your hair. Is this how he's supposed to do this? Should he be this bored?

"Say something nice."