Dick-Measuring Contest

This one is less of a game than a "choose-your-own-sexual-adventure" story.
There are three characters: You, your best friend, and a woman who can be either one of your girlfriends (or neither).

You can customize all these characters extensively, choosing from a variety of species and attributes (with a heavy focus on dicks).

You can even choose your own gender; you must have a dick, that's the point of the game; but you don't have to be male, you can be trans or nonbinary.

Once you've created the characters, the woman challenges you and your friend to, well, a dick-measuring contest.

You go through a series of measurements and tests, and whoever wins gets to have sex with her. The game has oral, vaginal, and anal sex. There are optional themes of size theft and cuck.