Sold my iPhone 6+ to a friend and he can't factory reset?

[boulderpictures]

I purchased the iPhone 7+ and today sold my 6+ to a friend. He and I logged into the phone with my 4-digit passcode, and he has my iCloud password but the factory reset isn't resetting. Is this a security thing? I assume that my iTunes and iCloud are tied together for that phone, I started that iTunes account way back on my IPhone 3G...am I missing a step somewhere?

Just a little more info:

The 6+ has a MetroPCS simm
The 7+ has a Verizon Wireless simm

Both phones show my gmail under account settings.

 

[iFrog]

Did you logged out of iCloud before you let him have it?

 

[zstairlessone]

You should have reset it first. Giving someone your iCloud account information was a very bad thing, no matter how much you trust them. I recommend you change your password immediately and don't use the same pin as you gave your friend either for your new iPhone.

 

[J. A.]

Before selling an iDevice, this has to be done:
What to do before you sell or give away your iPhone, iPad, or iPod touch
If you read through the instructions, you’ll find a way to erase your device remotely. If your friend can’t do it, try doing it yourself.