$ lsof -i tcp:80 -P -R
COMMAND     PID PPID USER   FD   TYPE  DEVICE SIZE/OFF NODE NAME
firefox-b 22312 7692    s  128u  IPv4 1191807      0t0  TCP xy:56688->ocsp.digicert.com:80 (ESTABLISHED)
firefox-b 22312 7692    s  139u  IPv4 1191808      0t0  TCP xy:56690->ocsp.digicert.com:80 (ESTABLISHED)