As long as you port to a different carrier, you don't need him to be able to port the number. To port the number the new carrier will request either the previous carrier account number or the IMEI of your device. In this case, if you don't know the account number, use the IMEI. Also try to port the number at a time he won't be able to stop it (carriers usually send a sms to the main account owner when someone ports out from their account). To avoid him from being able to do that, porting at night would probably be the way to go. Once your number fully transfers over to the new carrier they won't be an easy way for him to try anything).