A Possessive Virgin's Break

 "A Possessive Virgin's Break" ( Hitorijime, Vuājin Bureiku  独り占め、ヴァージンぶれいく)   is the second episode of the Imouto Paradise! 2 OVA. It was released on  October 4, 2013, produced and directed by studio Mary Jane.

Full Summary
The episode begins with Keiichi complimenting Ririna's body, and her still angry with him, for not knocking on the door once again. Keiichi notices that Ririna has changed her panties, and comments that she has already done it this morning. She responds by saying he is the one at fault for being too perverted. Keiichi accidentally sprays Momoka with water, which leads to her having to change in her room, and thinks that she has gained weight around her bottom. While she is still half naked, Keiichi walks in to apologize for splashing water all over her. Embarrassed, Momoka panics and tells Keiichi not to look at her butt or belly, mostly concerned about him noticing the 'weight gain', which is actually just body growth. Despite the incident, Momoka quickly forgives him, and tells him she is not mad. She also scolds him for not properly knocking first.

Keiichi tells Momoka that he had something to ask of her, so he wasn't able to hold himself back. Momoka get's the wrong idea, and suddenly invites him to her room. She tells him that she is ready now so he can do it anytime he wants, to Keiichi's confusion. Momoka thinks that he is unsatisfied, so she flashes him her panties, and takes her skirt off. Then Keiichi tells her that he actually just wanted to borrow some mechanical pencil lead, to her humiliation. However, she jumps onto him, unable to hold herself back, telling him it's all his fault. Momoka reveals that while she was cleaning him room, she found lots of porn magazines, and she took a peek inside, there were lots of things she didn't know about which she got interesting in. She asks Keiichi if they can try it. The two of them have sexual intercourse. After, Keiichi is shown also having sexual intercourse with Ririna, and she tells him that she loves him.