ゆるふわくんにはワケがある

Rintarou and Natsu are childhood friends who have always been together since they were small. Even after becoming high school students, Natsu is still a crybaby and Rintarou is still affected by his crying face. However, one day Natsu consults Rintarou about a female stalker and asks him. "I want you to pretend to be my lover. Rintarou agrees in order to protect Natsu but he’s perplexed by Natsuk’s “lover's appeal” everyday... Moreover, they even do lewd things to set the mood. The excitement is too much and when faced with the male side of the Natsu he doesn't know. Rintarou ends up not knowing what to do.. (Source: Gush, translated)