Yeah, it is. 本田 優美香 (the black-haired woman in red) is the wife of the protagonist. 鈴木 若菜 (short-haired woman with glasses) is his junior at work. From that Getchu page, it seems that the protagonist and his wife have been a couple since college and then got married. They're trying to build a home and family together, the husband by working at his job and the wife by working part-time at a family restaurant. Everything is fine and the protagonist is a good husband, except he's a little on the small side and bad at sex besides. The wife vaguely feels a sense of dissatisfaction with their bed life. While she is quite attractive and has a lot of sex appeal, she herself isn't aware of that. She's a bit of an airhead and faithful to her husband. Basically all the ingredients for a perfect netorare storm.
The girl with glasses, by the way, secretly likes the protagonist but knows he's married.