1. Have you been issued a legal notice for demand of money by this man? If yes, have you responded through your lawyer to it? Has the case already been filed in the court by this man? These questions need to be answered by you.
2. The FIR for sexual harassment which you have lodged against him is distinct from the 138 case. The filing of FIR against him by you does not place an embargo on his right to file a case of cheque bounce against you.
3. You have stated that the signature and handwriting on the cheque does not match your handwriting and signature. Be that as it may, if he has filed the case then firstly obtain bail from the court. Thereafter you may, depending on the facts of the case, move High Court to quash the case.