Rudgald said:
I also think that this is what the second to last and the last pages implied. "Bomb between them" means that Nagi IS misunderstanding why Hayate wants to stay by her side (this was also implied in earlier chapters) and when she will finally find out the explosion of negative emotions from her disappointment will open the path.
I think this also confirms that Hayate wants to stay with her out of pure gratitude - she saved him when he needed saving the most.
And lastly - hell yeah, the debt was finally paid off (mostly, lol) after all this time. :D
ohh. Guess they were still speaking figuratively about the "explosion" of negative emotions. I also thought it was just a typo for "bond".
Well, just gotta wonder what Hayate's planning then. He hasn't really been playing the nice guy lately.