The legal aspect is that second wife can also file for Bigamy. The SC has held in A. Subash Babu v. State of A.P., (2011) 7 SCC 616
S. 198 - Bigamy - Prosecution for - Expression ``aggrieved person'' under S. 198 - Scope, meaning, ambit and interpretation - Second spouse, whether an aggrieved person entitled to file complaint for offences under Ss. 494 and 495 IPC - Appellant concealing fact of his having an earlier living wife, and marrying Respondent 2 - Held, a woman with whom a second marriage is contracted by suppressing fact of former marriage is an ``aggrieved person'' for purposes of S. 198 CrPC and would be entitled to maintain a complaint under Ss. 494 and 495 IPC - S. 494 IPC does not restrict right of filing complaint to first wife only and there is no reason to read S. 494 IPC in a restricted manner - To achieve laudable object of monogamy, meaning of phrase ``aggrieved person'' has to be expanded - Expression ``aggrieved person'' denotes an elastic and an elusive concept - Its scope and meaning depends on diverse and variable factors - Further, S. 495 IPC punishes an aggravated form of bigamy and is an extension of S. 494 - Word ``concealment'' in S. 495 refers to concealment of former marriage from second wife - Therefore, second wife is an ``aggrieved person'' under S. 495 IPC - As S. 495 is an extension of S. 494 IPC, second wife is also an ``aggrieved person'' under S. 494 IPC - Considering the miseries inflicted on such second wife arising out of the gross fraud perpetrated upon her, further held, to debar second wife from filing complaint under S. 494 IPC would be the height of perversity, (2011) 7 SCC 616-A
However, on factual grounds; I would suggest you not to file any such case; because merely saying that you did not know of first marriage would start the prosecution but after ages; it would be proved that you had inkling etc. and thus you may not take the case to logical end.