Long vacation.
http://www.mangago.me/read-manga/shiranu_wa_omae_bakari/
http://www.mangago.me/read-manga/boku_no_kichiku_megane/
http://www.mangago.me/read-manga/desire/
http://www.mangago.me/read-manga/himegoto_asobi/
http://www.mangago.me/read-manga/ano_kado_wo_magatta_tokoro/
http://www.mangago.me/read-manga/dekichatta_danshi/
http://www.mangago.me/read-manga/karada_meate_de_warui_ka/
http://www.mangago.me/read-manga/omae_de_nakya_dame_mitai/
http://www.mangago.me/read-manga/katsuai_monster/
Any lists/recommendations for yaoi stories where the couple starts off as sex friends/ONS or goes from friends>sex friends>lovers?