Careless Cherry(2007)

Ukkari Cherry

5) Nemurenu Yoru ni Nomikonda Hoshi
Sawa is confessed to by Shiroi, a kouhai in his art club, but as he struggles to come to terms with being confessed to by a boy, Shiroi manages to act entirely too normal. Does Sawa really matter to him all that much? Contains art classroom sex and what may possibly be the mysterious usage of painting supplies as lube. Please do not attempt this at home.
(from Vices and Devices)