Purpose: This experiment investigated the effects of a book-sharing intervention implemented in coparenting homes on the conversations of preschoolers with their parents. Method: A multiple baseline design across behaviors was used to evaluate the effects of embedding decontextualized language utterances during book-sharing delivered by four families. A visual analysis, a two-level mixed-effects model, and a social validity evaluation were used to examine the varying effects of the program on mothers and fathers' storybook conversations. Results: Embedding decontextualized language prompts in books not only increased parental decontextualized language utterances, but most parents were able to maintain use of strategies without prompts in the books. The intervention effects were consistently higher for parents than for their children. Social validity results demonstrated parental satisfaction with program delivery and content. Conclusion: This study adds to the limited literature on father-child and mother-child decontextualized conversations during book-sharing and illustrates a feasible and adaptable way of promoting language experiences in the home that yield engaging decontextualized conversations in meaningful book-reading contexts.