Just wait until they find your wife's phone number. (OK, this wasn't datadog, but some similarly aggressive headhunting agency went from calling me to calling my wife - who is in no way affiliated with my company - to ask her if she could tell me about how they could help me in hiring, yadda yadda.)
I had something similar happen with a Facebook recruiter. I didn't reply to her first two emails so she started emailing my mom to try to get in touch with me. My mom called me because she thought it was a phishing email. I had never had that happen before.
