False affidavit in Family court for creating disturbance in marriage

I am a PSB employee. I am going to marry a girl soon. Her ex (Nath) has threatened over phone that he will destroy her life by cancelling our marriage. Nath tried every possible way so that I would cancel it. Like sending old pics, screenshot of their past conversation and also some false instigating data etc. The girl already has denied to continue relationship with him months before my proposal. Now Nath has made an "Family Court Affidavit" stating that they are married in a temple and in some notary on dtd 29Jan2021 (which is totally false). The court hearing date is one day before our marriage. Nath threaten me saying that "You are talking with my wife and going to do 2nd marriage, so you will face legal/other consequences". To which I replied him "do whatever you want to do with your lies. But don't disturb me." Nath seems to be a psycho and unable to think in a right way, also he is not in a mood to make things normal. I am worried about the court affidavit and the date. If we are going to marry on that date, is their any legal trouble for us?