All no longer virgins... should sing 童贞 instead.
Those singing in the first post are likely from NTU alumni.
There is a larger Nanyang alumni (not NTU) and alumni choir compromising of rich grandparents from Singapore, Malaysia, Philippines, Indonesia, Thailand and China.
Both groups are not friendly to each other.
Likewise Chinese High and HwaChong, formed two different alumni for different generations because HCJC got womenfolks.