Electronic evidence will play a crucial role in your case. The investigating officer will be able to obtain the source of information from your mobile, even if you have deleted all records. You cannot deny the fact that you knowingly shared your ex-girlfriend’s contact number to pretend she was a call girl. As a result, you have committed offenses under sections 354-D, 500, and 509 of the Indian Penal Code, as well as Section 67-A of the Information & Technology Act.
By sharing her number, you insulted the modesty of your ex-girlfriend, which is an offense under section 509 of the IPC. Disrespecting a woman is an offense of defamation under section 500 of IPC. Your intention was for someone to call her mobile and advance their sexual desire. Her husband has the right to initiate criminal proceedings against you by lodging an FIR under the aforementioned sections.
The privacy policy of WhatsApp clearly states that messages are encrypted, and no third party, not even WhatsApp, can read the transmitted messages. Therefore, you cannot say that someone else sent her contact number in the WhatsApp chat. Any information shared on WhatsApp is an electronic evidence and admissible under section 65-B of the Indian Evidence Act. Hence, this electronic evidence will prove your guilt, and you cannot deny the truth of this evidence.
It would be best to settle this matter out of court by apologizing for your actions and saying sorry to your ex-girlfriend. Her husband has not yet filed any FIR against you, giving you the opportunity to resolve the matter outside of court. Taking responsibility for your actions and apologizing will help resolve the issue before the FIR is filed. However, if her husband files an FIR, you cannot compromise because some of these offenses are non-compoundable.