I thought I would share some, er, experimentation in love.
In my Vault 404, Larry the Lothario has been 'dancing' with every female vault-member so that every woman is pregnant and this seems to have been accomplished with no less happiness on the part of Larry's conquests or indeed for Larry himself.
(though the other men lack the same 100% contentedness)
I expect this will do little for the gene pool of the 'Republic of Larry' but we'll see how it goes.
Simply out of curiosity, to see how Bethesda would handle greater in-breeding,
Larry is 'pleased to be with his family' when with his daughter in the Living Quarters.
(phew)
But extensive playing the field would appear to be just fine...