7 Online Dating “Rules” to Follow – and 5 to Break. Dr. Ronn (5) Wait 24 hours to respond. Responding to email within 24 – 72 hours is considered prompt. At the end of the date he suggested doing it again sometime. He didn't text me for EXACTLY 3 days (I'm talking 72 hours to the dot) after the first. Online dating 72 hour rule. Mums battle out the Kissing on a VERY affectionate display as she gives another glimpse of glittering engagement ring on a.