Not sure if this is correct place for this subject

google tracking your every move? big data matching?

this what happened and want to know if people have come across this
situation and way to unassociated gmails with ones own account.

so this is what happened last week.

mom got dad a new smartphone but couldnt remember his email password

so I logged on mine pc and tried to login to gmail on browser and try the password I thought it was (as I setup his old phone for him years ago)
and seems they beefed up security..


it came up with verify who you are.. is this your phone number and shows end 3 digits,.. and provided moms mobile number.. I think
she used his google email on her phone at one stage. didnt even list his old phone number at all.

so I typed in her phone number rest of it and sure it worked and activated his gmail again..so now would login to
the new smart phone to activate play store and down his apps etc.

then the next thing that happened was i got emails to my own gmail and xtra accounts saying someone has logged into your account is this correct. wtf.

so now they think dads email is another one of mine now cos I logged in via my pc??

they are doing data matching pc ids etc maybe old cookies?

I deleted emails as I knew it was talking about what we just did as listed dads gmail

now I dont know how to remove his linking to me. for my google account

could be dangerous,, imagine if dad did something it could be me thats blamed LOL

so again any way to login to google account and unselect gmails of other peoples under my name as I didnt find anything when looked and if I unselect will it
destroy his email setup again.. or should I just ignore it and leave it as is
as nothing has happened since.