Is dating and/or having sex with someone who looks like you narcissistic?

Would you consider dating and/or having sex with someone who looks like you narcissistic, or is it a function of the attempts to pass on what you believe are your superior genes, which this person must share, seeing as they resemble you? Or could it be some Freudian, psychological, Oedipal, subconscious lusting for a parent? Thoughts?