I should have known. I should have seen the signs.
6 seconds sound clip from the How to Train Your Dragon movie soundboard.
You can hear this line at 01:04:48 in the Blu-ray version of the movie.
Quote context
[...]
- No! No!
- Get him!
- No, no! Please don't hurt him! Please don't hurt him.
- I should have known. I should have seen the signs.
- I know we did. That was before...
- So everything in the ring, a trick? A lie?
- I screwed up. I should have told you before now. I just...
- Take this out on me, be mad at me, but please, just don't hurt Toothless.
[...]