When I was 10 more or less. My parents use to work all day: one day, a new babysitter arrived, she was a few years older than us, but a bit smaller and thinner than my sister, one day, the babysitter offered her back for a piggyback

and I was suprised to see that skinny girl carrying a taller and heavier girl smiling all the way

from that moment I think... because I started to pay attention at school when a girl carry an other girl