Answered by Shaykh Rami Nsour
Question: Assalam ‘aleykum,
Should I renew my wudu if I touch a woman?
Answer: Wa alaykum as salam wa rahmatulah.
If someone touches another person from whom pleasure can normally be derived from, and pleasure is either intended or found, wudu is broken.
Thus, if a man touches a woman either intending pleasure or finds it after touching with no intention, then the wudu is broken.
Rami
Source: http://seekershub.org/ans-blog/2016/04/08/13590/