See The Time Traveller's Wife by Audrey Niffenegger.
If by "clone" you are referring to reality as opposed to science fiction,
i.e. someone with the same genetic material as me but not the same age
or otherwise similar to me, then it would seem to be much like incest.
But if you mean the science fiction version where there are suddenly
two of me with the same experiences until we now start to diverge, it
would seem to be more like masturbation, like the example in The Time
Traveller's Wife, so why not?