2nd wave is the one which frightened insecure men, and had some strong anti porn and anti sex messages from a few proponents. 3rd wave, in short, is why don't we all get along, sex is awesome, and if we help men with some of their problems with toxic masculinity, then everyone is better off.

edit: Here's a good & brief overview of feminism's waves - http://www.pacificu.edu/about-us/news-events/three-waves-fem...