Use one adroid phone as a headset for another android phone

[AC Question]

I have two android phones; one with a sim card (and the ability to place/receive calls); and one without a sim card. What I want to do is to use Bluetooth to connect these two devices and place or receive calls using the phone that doesn't have a sim card (essentially turning the second phone into a wireless Bluetooth headset for the first phone). Is this possible without using a third party app (or with a third-party app)?

 

[hallux]

I'm curious as to why. If you can hold one up to your ear to talk, why not hold the other (with the SIM card in it) up?

To answer the question, no. A phone doesn't carry the "headset" profile in the Bluetooth stack, it can only host a device that connects using a headset profile.