John Gill Commentary Ezekiel 16:28

"Thou hast played the harlot also with the Assyrians, because thou wast insatiable; yea, thou hast played the harlot with them, and yet thou wast not satisfied." — Ezekiel 16:28 (ASV)

You have played the whore also with the Assyrians
By entering into alliances with them, and worshipping their idols; which was done in the times of Ahaz, who sent to Tiglathpileser king of Assyria for help, and to Damascus for the fashion of the altar there, and built one according to it, (2 Kings 7:10 2 Kings 7:11);

because you were unsatiable ;
not content with the alliance and idolatries of the Egyptians:

yes, you have played the harlot with them ;
with the Assyrians: and yet could not be satisfied ;
with their idols, and the worship of them, but sought out new gods, and new modes of worship;

like a lewd woman, who having prostituted herself to one and to another, yet remains insatiable, and seeks out for other lovers.