Teacher struck off
James Kelly, from Derbyshire, initiated romances with two parents and "incessantly" contacted three others between 1997 and 2006, England's General Teaching Council's professional conduct committee heard.
Mr Kelly, who taught at Curbar primary in Hope Valley and St John's primary, in Belper, both in Derbyshire, obtained one woman's telephone number from her son's school trip consent form, according to evidence.
John Flynn, headteacher at Curbar primary, said: "The rumour mill was working over time, and the reputation of the school was crumbling as a result of his actions.
"People who were considering sending their children to our school did not, and you cannot quantify what that meant to the school. It had a very real effect."
Curbar primary formally investigated Mr Kelly's behaviour after complaints from parents, but he resigned in September 2000.
He joined St John's primary soon after, then started a relationship with a second parent, which led to the breakdown of her marriage, the committee heard.
Mr Kelly received a two-year prohibition order, after which he can apply for his registration to be restored.