The thing under the bed

So the premise for this story is pretty straightforward but still fun. I play a bizarre tentacle monster under the bed of a working class lady, the relationship starts rocky till understanding is reached and then wholesomeness happens. There's loads of ways to play this but the basic premise is the same, the thing under the bed becomes like a pet who feeds of her sexual energy and secretions, it's symbiotic and has grounds for interesting background story development as her life turns upside down, inside out and is somewhere between cosmic horror and sexual fantasy.