Well I don't know why I didn't add slapping sounds before but you made me realize it would be a great value to the game... Especially since MC loves slapping butts haha... You know what? I'll add this right away!
Then think about adding also some background music, something chill and nice, like that track from main menu, I like it.
Because I think that just alone slap sound out of silence and nowhere will sound weird and too suddenly, so gonna scary or stun to deaf some people who was not aware and was playing with high volume level without paying attention.
Female moans also would be awesome.
I hope we didn't opened a Pandora's Box, because I believe proper sound design can take not less time and efforts, than animations and plot.