Maybe there was a reason she avoided sex for so long. Never mind the familial responsibilities that kept her from any kind of social life. Truth be told, she could have made time for a quickie now and then.
Maybe she avoided sex for nearly a decade because she didn't want to admit that she loved the way a cock filled her up, stretched her, made her feel full. Not quite a nympho, she just had a longing to be fucked, often and well. Like Audrey II, her hungry pussy constantly pleaded "feed me."
Afraid of how her need to be used made her feel, how desperate she'd get sometimes, she quit cold turkey. She stopped seeking sexual partners, stopped using penetrating toys. No penetration meant the whore inside her would sleep. Best not to rile her up. Be a good girl and lock the whore away. Do not feed her lust for sex.
It was difficult at first, denying herself. Going through withdrawal much as any addict would. Oh, she didn't stop masturbating. She just adjusted to reaching orgasm solely from clitoral stimulation, her pussy desperately spasming around... nothing.
She stayed busy with work and taking care of her dying mother. Her friends slowly stopped calling. She stopped dating. She became used to the hollow, empty feeling.
Then her mother died.
When you've devote years to caring for someone, halting your own life because you were always "the responsible one," and that someone dies, there's an instant crater. An instant uncomfortable silence that must be filled.
You have time now that you hadn't had before. But you don't know what to fill that time with. Finding yourself alone in a silent house is frightening. Being alone with your thoughts can be terrifying.
She was finally free of all of her obligations, her responsibilities. She was finally alone. Completely alone... too alone.