Why was my 9gag account automatically logged on?

[Dani]

So, i have a 9gag account that i haven't used in over a year and so i go on facebook and log in. then i open a new tab and open 9gag and my account is logged on already. So i know what you;re gonna say and no i didn't leave it logged on a year ago because this is a new laptop that i got this month so im a bit freaked out as to how it was logged on already. Unless because my facebook and my 9gag use the same email it does that automatically? does anyone have experience with this or any help? its probably jsut me being a bit dumb but whatever, thanks if anyone can help x
Edit: Ive already googled it and no websites say anything about facebook and 9gag being connected.

[kkkkkkkkkkk]

google it