from the women's charter:
Grounds on which marriage is voidable
106. A marriage which takes place after 1st June 1981 shall be voidable on the following grounds only:
(a) that the marriage has not been consummated owing to the incapacity of either party to consummate it;
(b) that the marriage has not been consummated owing to the wilful refusal of the defendant to consummate it;
(c) that either party to the marriage did not validly consent to it, whether in consequence of duress, mistake, unsoundness of mind or otherwise;
(d) that at the time of the marriage either party, though capable of giving a valid consent, was suffering (whether continuously or intermittently) from mental disorder within the meaning of the Mental Disorders and Treatment Act (Cap. 178) of such a kind or to such an extent as to be unfit for marriage;
(e) that at the time of the marriage the defendant was suffering from venereal disease in a communicable form;
(f) that at the time of the marriage the defendant was pregnant by some person other than the plaintiff.
if a child were to be born under circumstances (d) to (f), the child would still be legimate, but marriage contract still voidable. to me, it's not a matter of twisting the legal technicalities to escape the definition divorce or not... because nobody really wants to be in the above situations knowingly..