i think the author is trying to show that the more Takahashi falls the more anxiety he feels - like he's gonna give his all if ever? (take the fact that Uchida is a heart breaker. that might happen to Takashi as well - that kind of anxiety)
Uchida never told Takahashi that he loved him, so Takahashi probably thought that he was just fooling around.
haha cute but the reason for the breakup is the dumbest ever! "I'm sorry I love you, let's break up"?? wtf?!