Waiting for the right time, Zeus spotted Hera bathing in a secluded falls. Immediately Zeus transformed himself into a cuckoo and created a thunderstorm that drenched him thoroughly. Finding the little bird wet and hurt, the kindly Hera picked him up and cradle him close to her chest. In the blink of an eye Zeus immediately changed back into his usual form and raped her.
To save herself and not to lose her dignity, a wedding was arranged and everyone was jubilant for Hera (at that time became the Queen of the Heavens). Everyone thought that she would manage to change Zeus a little bit.
According to some sources, their marriage got off to a good start, with their honeymoon lasting over 300 years!