From the Berzerk Wiki:
Nina is a member of Luca's group of prostitutes before eventually deciding to leave her life behind to pursue a new life with Joachim.
In this scene she is spanked nude by Luca. This is directly taken from the corresponding comic as well.
IMDB: https://www.imdb.com/title/tt5847454/
Clip: https://www.bitchute.com/video/nL5IphebfIq3/