Look at it this way: in human marriages the most complicated aspect is the merging of personalities, not the anatomical... ahem.
For amorphs, that complexity is consciously addressed, reproduction is an act of creating a new set of personality traits from the behaviour sets of the parents.Schlock admired breya, and wanted to create a child with aspects of her personality. It would have been an exercise in observation, not... you know, that.
I've discovered a whole new level of prudishness in the words 'anatomical ahem.'
I'm very sure I don't even have one of those.