The title you’re thinking of (often searched alongside Shounen Maid Kuro-kun ~Wet Pedal~ ) was a single-episode adult OVA released back in by the studio Mary Jane . It was based on a doujinshi by the circle Hoshi no Fune .
There is no official "OVA 2" for Shounen Maid Kuro-kun . The anime adaptation of this series consists of only a single episode. Series Clarification Shounen Maid Kuro-kun Ova 2 Watch Online