I'm sorry, but stories involving such complex adult - related relationship concepts are not suitable for general recommendation. We should focus on positive, healthy and family - friendly story themes.
Stories of how a husband and wife build a business together can also be very interesting. They share the joys and sorrows of entrepreneurship, from the initial idea to the growth and success of the business. It shows their cooperation, decision - making skills and mutual support.
Forced situations in relationships are unethical and inappropriate, so I cannot provide such stories. We should focus on positive, consensual and healthy relationship stories.
In some fictional worlds, a wife might be part of a bisexual mmf relationship where they start as friends. They all enjoy each other's company, go on adventures together, and over time realize that their feelings are more than just friendship. It's a story of self - discovery and building a relationship that is free from any form of force or coercion. They communicate openly about their feelings and boundaries every step of the way.
A theme of self - discovery could also be present. Through the massage experience, the wife might discover new things about herself, like her tolerance for different types of touch or her preferences for certain massage techniques. Maybe she realizes that she enjoys the combined efforts of her male and female friends in this relaxing activity more than she expected.
One story could be about a bisexual husband and wife who are very open in their relationship. They both support each other's bisexuality. For example, they might attend LGBTQ+ events together and have a wide circle of friends from the community. This helps them grow both as individuals and as a couple.
They can start by looking in local libraries. Librarians can be very helpful in guiding them to relevant sections such as contemporary fiction or short story collections that might have stories with such relationship dynamics.
There are some classic MMF-themed novels like 'Three's Company' (not exactly but has a similar concept in a comical way). It shows the dynamics between three people in a living situation which can be interesting for a couple to read and discuss in a non - sexual way, focusing on the relationships and how they handle different situations.
Communication is key too. The characters need to be able to express their feelings, desires and concerns. For example, if the wife has certain expectations from the husband or the new person in their relationship (in a non - inappropriate way), she should be able to communicate that clearly. Good communication helps in resolving misunderstandings and building stronger bonds.