Is it a relapse?

No? Especially if you didn’t seek it out. It’s like when there’s a sex scene in a movie. Sometimes you can’t control what you see, things happen. But in this case if you actively watched it then yes.

Accidentally watched does not exist dude, you did that on purpose, yes it’s a relapse

Nah

Accidentally watched? Really? Accidentally opened it out of curiosity like “what is this?” And closing it immediately once you realize what it is, that’s no relapse. But watching it implies you sat there watching it from start to finish. You relapsed then, and since it was a start to finish watching it, it implies you were invested/interested in it too, which would mean you’re gay.

Weird friends