Sims 4 Ps4 Vampire won't stop drinking plasma packs?

Just a weird question...I had a vampire sim in my household with several plasma packs in her inventory. She got invited to a party and would not stop drinking the plasma packs, even though her thirst was full (free will turned all the way up). I had to sell all the packs to get her to stop. She also had plasma fruit in her inventory, but was not eating that.

I have two other vampires in my household and they went on a date together, both of them behaved the same way and wouldn't stop drinking the packs. Eventually they went home and are no longer drinking them on their own free will. Does anyone know why my sims were doing this? Is it just tied to a social event somehow? Any help would be appreciated.