This gives the games more replay value, since the player can focus on a different girl each time, trying to get a different ending.
Dating sims such as Tokimeki Memorial often revolve almost entirely around relationship-building, usually featuring complex character interactions and branching dialogue trees, and often presenting the player's possible responses word-for-word as the player character would say them.
The gameplay involves conversing with a selection of girls, attempting to increase their internal "love meter" through correct choices of dialogue.
The comic-book-esque shading it had was really great.
Dating sims, or relationship simulation role-playing games (RS-RPG), are a video game subgenre of simulation games, usually Japanese, with romantic elements.
"Lazy Fat Boobed Cow" is something very harsh to say to a stranger no matter how many "female sexual stimulants" she's hopped up on. I'm glad this one didn't have any annoying mouse shaking additions.
If this was a consensual BDSM simulator, it'd make more sense because that kind of thing happens with BDSM all the time, so long as it's in each other's comfort zones. Rating 4 stars for the art, because I really really loved the art style.
They are also sometimes put under the category of neoromance.