Did Augustus Change the Law?

Adultery was considered so harsh that it isn't often prosecuted. It's something that perhaps comes up at times of instability, or when an emperor wants to really put his mark on roman private life. But apart from augustus and domitian, it's there. The next law he brings in is in 90, which is a year after he's exiled his granddaughter. Domitian really brings it back with a vengeance. They stayed on the books for centuries, and really only started to be repealed when constantine embraced christianity.