I accidently liked this guys photo on Instagram?!?

[SayCheese]

So a guy who i know i was stalking his Instagram lol and i went onto photos other people took of him and i saw a video of him and i accidently clicked like and unliked it straight away then i changed my username removed my name and put my account on private. I'm so scared that his friend will be like to the guy, she liked that video u were in but hopefully because i unliked it nobody will know. Please help I'm so scared right now.
Also does that little message notification pop up at the top of the screen every time someone likes a photo or do you think he would of had it turned off. It's also 2am in the morning

[Michael]

If you unlike it know one will know unless the person who put the video up told instagram to send him a message when one of his photos where like, but him having a public profile that's not likely.