I'm looking for an h-manga where 2 boys are playing videogames using controllers and the mother of one of the kids starts teasing and sucking the other boy (a friend of the former). The son is so engrossed with the game that he doesn't even notice. Then the mother tells her son that she has seen the game her son was looking forward to playing was for sale at a shop (before official release of that game). After the son left the house, the mother and the other boy continued their business.
I think the story starts off with the woman and the boy having sex at the toilet.
Thanks in advance!