Marrying by any spouse during the subsistence of a valid marriage, [Without divorce from competenet court], with any other person tantamounts to the offence of Bigamy.
Hence the marriage of your sister and her former husband is Bigamy, and it is an offence under IPC , and it is not regarded as a valid marriage.
G.L.N. Prasad (Retired employee.) 28 August 2018
The question is what is bothering you at present, when both have married ignoring law and have their families and living happily
The law is sensitive and one can not give expert opinion without knowing facts and circumstances. Once it is illegal means illegal and there are no exemptions from such ilelgality what ever the circumstances are. But at the same time, law can not force a spouse to live with the other without interest or love.
P. Venu (Advocate) 28 August 2018
Admittedly, the second marriagea have taken place couple of decades ago. In all probability, both the couples are settled in life with grown up children. That being the situation, what is the point of botheration now?
SUNIL KUMAR (apprentice) 30 August 2018