Dua to protect yourself from the fitnah of the opposite gender:

"My Lord,And unless You turn away their plot from me,I might incline towards them and [thus] be of the ignorant."
Rabbi waillaa tasrif 'annee kaydahunna asbu ilayhinna waakun minal-jaahileen
Surah Yusuf ,verse 33
This is the supplication of Prophet Yusuf alaihissalaam.