Nexxius parent
Reply to the texts with "dick pics"...but of horse or cow penis. Chances are pretty good he will block you or just stop soon after the first.
For email...auto reply with links to https://en.wikipedia.org/wiki/Goatse.cx
or go for the the rabbit hole and toss out a random OnlyFans /Ashley Madison / Grinder page.
Responding at all seems like an incredibly bad idea.