If a player celebrates by lifting their shirt up to their waist, what should the referee do?

When a player lifts their shirt up to their waist as a form of celebration, it is generally viewed as a lighthearted and informal gesture. In most football governing bodies' regulations, this specific action does not warrant disciplinary action such as a yellow card. There are exceptions for actions considered excessively provocative or inappropriate, but simply lifting a shirt to the waist during a celebration is typically seen as harmless.

Allowing the incident to proceed without issuing a card aligns with the spirit of the game, which values sportsmanship and the enjoyment of celebrating goals. Referees are encouraged to differentiate between celebration and unsporting behavior, focusing on actions that could escalate or create a disruption, rather than minor celebratory gestures that are generally acceptable. In this case, since the action does not disrupt the game or provoke negative reactions, no formal punitive measure is needed.