Who was Queen Nefertitis son?

It is possible as Smenkhkare's face shows resemblance between Nefertiti and Akhenaten, it is most likely Nefertiti was Smenkhkare's co-regent explaining why their names are close together, on Smenkhkare's year 3 Stela, he says he is the son of Ra Neferneferuaten (Nefertiti) and that he was the beloved of Waenre (Akhenaten). I'm assuming that to be called the king's beloved it means you are his son and therefore a title, however it is only a possibility.