Does smiling or laughter break wudu? Lets say one laughed once and realize it would that break wudu?
No, they do not have an influence on wudu. There was a difference of opinion on whether laughter during the prayer would nullify both the prayer and the wudu, but the stronger opinion is that it only nullifies the prayer without affecting the wudu.
- Fatwa from the Qatari Fatwa Authority (Arabic PDF)