I'll be around.
我就在附近。/我会留在这里的。
A: Will I be able to meet you again?
我们还会再见面吗？
B: Of course. I'll be around.
当然了，我就在这儿附近。

(It) Doesn't fit.
不可能。/不合适。
A: Your wife said she went to visit her sister.
你妻子说去看她妹妹了。
B: It doesn't fit. My wife and her sister don't like each other.
不可能，她们姐妹俩关系不好。