How to make sure that ww animation doesn't change in sex between npc-npc sims

[daejung2]

I checked related settings( controlled progression, rapid climax prevention, manual progression), and set the duration of npc sims sex to 999 minute, but the sex between the npc-npc sims end quickly, and the ww animations are randomly changed.

Is the relationship between npc sims completely out of control?