When a group of 2-5 men descend onto a willing female participant, sexually, as if in a race car meeting scenario, to take turn pleasuring or being pleasured by the woman, who is usually on her back, but can also be seated/kneeling. The scene depicts very similarly to what the pit crew paddocks are like during a race meeting, each guy taking his tool to the action.
She was enjoying some pitcrewing for her special celebration, as a new experience. It was very hot.