Metro Thoughts: Genetics...

During one of my daily subway travels to work, my restless mind came across the current topic of this post.
I was at the time looking at a family (parents and 2 teenagers), where the boy was an exact copy of his father and the same with daughter and mother...
My question is: Shouldn't these teenagers, in a strange way, feel attracted to each other?! Either physically, mentally or both?! Like their parents are/were?!