核心问题
If you tell your father what you've done, he'll be more than a little angry. more than a little angry 是指“生一点儿气”，还是“非常生气”？
词典解答
为便于理解,我们可以把 more than 理解为 not。more than a little 近似于 not a little,是“很”“非常”的意思(参见 a bit/a little)。上面的句子可以译为:
如果你把所做的事告诉你父亲，他会非常生气的。再如：
You have more than a little problem, the manager thought. (Dan Brown, The Da Vinci Code) 你的问题可不小, 经理想。(《达·芬奇密码》)