Nonke Bishounen o Homo Doukyuusei no Tamariba ni Iretemita

A straight bishonen is ridiculed for his pretty boy face.
That was all well and good until some ruff tuff gay classmates set their target on him, One day he gets invited to their cruising house to meet some 'friends' in a dark room, this pretty boy's day of sexual objectification begin.

[From DLsite]