No.
Each oAuth key belongs to one account.
When you login it’s with username/oAuth keypair
If you make a oAuth token for foo
You must login with foo and foo’s oAuth
You can’t login with bob and foo’s oAuth
No.
Each oAuth key belongs to one account.
When you login it’s with username/oAuth keypair
If you make a oAuth token for foo
You must login with foo and foo’s oAuth
You can’t login with bob and foo’s oAuth