Why attraction does exist towards opposit sex ?

Answer 1

It is in the genes. All living bodies are attracted to the opposite sex for procreation.

Answer 2

you r wrong. attraction does exits with even same sex.
Attraction is feeling good and interesting, liking him/her being with u.

but this is for u.---
U r staying with urself since ur childhood. and u know what it is like being with same sex. People are more attracted towards those which they dont have. for eg:. you cannot tickle urself, even if u, u wont feel that like the other tickle u. There is a long scientific reason behind this.
So get attracted and attract others toooo..