Does touching the opposite gender invalidate ablution?
It is a sin for man to touch a stranger woman; however, Hanafi school states that minor ablution of both man and woman are not invalidated in such situation (Mawsili, al-Ikhtiyar, I, 54). According to Shafi’i school, if a person touches the bare skin of the opposite gender with whom she/he has no obstacle to marry in religious terms, ablutions of both are invalidated. (Mawardi, al-Hawi, I, 183-187). However, touching hair or nail of the opposite gender does not invalidate ablution.
Source: Presidency Of Religious Affairs The Turkey, High Board of Religious Affairs FATWAS