The "Sorry Not Sorry" singer posted a ton of snapshots to her Instagram Story from her arcade game-filled celebration, where she got silly wearing a crown and posed wearing a simple jeans and tee look. Demi obviously had a blast with everyone, making us superjealous of her night, but no more than when we saw her with Wilmer.
The couple, who dated for six years, broke up last Summer, but have remained close friends, posing for another adorable photo together in early June. Of their relationship, Demi has said: "Being sick was always a part of my relationship with him; I always had something wrong with me. I needed to let go of that. It was hard to depart from somebody who saw everything, but it may be nice to start fresh with somebody."
Keep reading for more photos of Demi's celebration.