I was playing around with the game, first with a penis, then a vagina, and some of the text doesn't fit with the genitalia, and the sex scene with Seth outright changes the genitalia. I personally think that there should be some more animations and text correlated to what genitalia you choose. It's just something I found while trying to see what has been completed. I'm well aware that it's 0.3 but sometime in the future it would be nice to see some more content that fits with text and animations. Also, there is some really bad lag on the Seth date/sex scene, but not game-breaking, and I have a terri-bad shovel-ware toaster PC. A friend of mine told me about this game today as of this post, and I really like it, and that's why I'm posting this. I hope some of these things get addressed/fixed in 0.4, and I really look forward to it!
There isn't officially a vagina in the game. The slit is for a male genital slit, hence the character is default male for the moment.