How to turn off automatic sign in - ESPN and all apps on iPad

How do I turn off Xfinity automatic sign in.  When using my iPad...I click on the ESPN app but it it ALWAYS signs in to my girlfriend's Xfinity account (who doesn't have full ESPN access).  I cannot log into my xfinity account on her WiFi or mine.  Why is that?  How do I turn off Xfinity automatic sign in on ALL apps?   It's incredibly frustrating.  I don't want to be Xfinity automatically signed in on ANY app.  Frankly, I should be able to login in with any id and password I have access to.  In this case, I have two accounts but automatically logs into the one I don't want.  How can we fix this?  Surely there's a way.