Ashbound by Lilith Ember

She came to stabilize the heat. They claimed her instead.

Rhea Brooks is a curvy thermal-systems engineer hired for five days to recalibrate the primary heat exchangers at Ashbound, a private geothermal compound built into a Cascade volcanic ridge. The two owners—Cassian Vale, controlled and intense, and Theo Hart, warmer but no less possessive—keep her on site when ash fall seals the mountain road. What begins as overnight sensor work becomes a why-choose claiming in the glass living level above the vents.

They take her together: mouths, hands, the full stretch of being filled by both men at once. She keeps her agency, asks for what she wants, and chooses the key when the road finally opens.

Ashbound is a high-heat MMF why-choose erotic romance with emotional stakes, possessive attentive heroes, graphic explicit content (including double penetration), and a heroine who decides her own ending. No fade-to-black. Adults only.