HOW THE HELL?

HOW IS IT POSSIBLE FOR SOMEONE WHO DID NOT FOLLOW ME LIKED MY INSTA PIC,?

OK, a so called (this-long- lost -far -away- land- who -just- died- in -the- skatepark- I- guess- no- I -was- just- joking- but- really -I -hated - him-so- much- friend) liked one of my pic in instagram.
ok, I guess u gonna think, that "hey he's just liking ur photos, whats wrong with someone liking it", but hey its not because of that its just doenst make any sense..

Alright, not so long and faraway land ago (?), we followed each other right.. ok I accepted his req while my acc is on private.. then after months later, we fought, and I secretly unfollowed him, so ok. And one day I posted a pic and he liked it, so I thought when u unfollow a person tru ur private acc, they wont see ur pics in their timeline right? And I was wrong, they can still see ur pic even after u unfollowed them cause u alr accepted them way before when they followed u. Then one day I decided to go tru his profile and check on his followers, but HELL NAWWW... I found out that he didnt follow me liao.. SO HOW THE HELL DID HE GET TO LIKE MY PHOTOS?
Well I did an experiment of what happened using my sis instacc:

Already a follower-> unfollow her -> she can still see-> her acc unfollowed me-> she cant see cause its on private..

AAND IM STILL WONDERING HOW IN THE FREAKING FOREST CAN HE SEE AND LIKED MY PRIVATE PHOTOS EVEN WHEN WE DIDNT FOLLOW EACH OTHER AT ALL?!

Well I may think that its not a big deal for someone I hated so much liked my photos... BUT hell naww, HOW LAAAA?
His face liking my photos, is really getting on my nerves... its making me so curious..

Haaaaaiiiiiiisssssssss,
Kahhh..... want to sleep ah
Night kk..

-hyqism