There are no words to express just how relieved the girl is that Lea doesn't take what she said badly, really. She even lets out a slight sigh of relief, but she's very busy trying to take in his words at the same time! She wouldn't want to ignore them when he's explaining himself.

".. It sounds like the two of you are close though." Lea and his friend, that is. Which is nice to hear - and also something Madoka can understand, no matter what kind of differences there may be between both of their worlds. Friends are something universal. "Have you two always been friends? This whole time?" After all, Lea certainly isn't a kid anymore by now!