2 olika nummer på Whatsapp?
Din kompis har fel. faq.whatsapp.com/general/verification/using-one-whatsapp-account-on-multiple-phones-or-with-multiple-phone-numbers/
Your WhatsApp account can only be verified with one number on one phone. If you have a dual SIM phone, please note that you still must choose one number to verify with WhatsApp. There is no option to have a WhatsApp account with two phone numbers.