Stone lover

When the fog falls here, it snakes and disperses like its alive. There is a pond in the graveyard near my home where certain kinds of fog create thillers amongst the stones.
On nights like this, I rush to see the pond. The fountain in the center gushing torrents of mist, gaurded by a stone angel keeping her perpetual vigil on the residence.
I've had nightmares and dreams of her.
First she hovers while I ponder the lives of those around me. Slowly curling her cloud-like tendrils 'round my legs to drag me into the abyss beside her. Her caress teases my thighs until im both terrified and aroused that I wake.
The next night I approach her first and her concrete dress gives when I lift it. Her expression does not change but she regards me and I oblige. She is smooth and firm and cold. I am wet and weary and wanting. When she closes her eyes, I break my fingers inside her and wake....which is the dream? Which is the nightmare?