Game Tomodachi no Onnanoko to Onsen Ryokou de Yaru Hanashi NTRver.

What if... Sakamoto hadn't step into the scene where Mari was taking a mixed bath with a group of strangers?

Mari Himeya goes on a lovey-dovey hot spring trip alone with her game-loving boyfriend. However, her boyfriend becomes obsessed with the retro games at the hotel and leaves Mari alone. Unknowingly, she is picked up by two burly college rugby players... Can these rugby players, with their voracious sexual appetites, resist the temptation to show each other off? Can Mari keep her fidelity to her boyfriend?

Note: Follows the opposite development from the lovemaking version.