He has suggested that teens should limit their sexual contact to touching, fondling and pleasuring each other.
"Sexual behaviour is often unsafe in adolescence. Teenagers have more sexual partners and may use condoms inconsistently or unsuccessfully," the Sun quoted Donaldson, as saying.
He suggests: "Think of all the lovely sexy things you can do without actually 'doing it'.
"And if you do 'do it', be safe and use a condom," he added.
His 'stop-short' guidance comes after an explosion in teen pregnancies.
However, Donaldson was branded 'grossly irresponsible' by a parents' pressure group.
Norman Wells of Family and Youth Concern said: "He should stress the benefits of saving sex for marriage."
Over 3,000 girls under 16 gave birth in England and Wales in 2006 and 4,700 had an abortion.