Even So, I Still Want to Be Your Boyfriend Tomorrow.

Kouhei and Mako are a couple in love. However, Kouhei is worried because Mako is very unwilling when it comes to having sex with him. On one such day, he hears a proposal from Mako: how about partner swapping sex with another couple? A shocking work that opens a new door of immorality! (Source: Young Magazine Web, translated)