like a dog with two tails可不是“像长着两条尾巴的狗”，真实意思是“得意洋洋；高兴得什么似的；无比高兴；非常开心”。

【例句】
The old lady waslike a dog with two tails when her son and his wife came home from Australia.
看到儿子及儿媳从澳大利亚回来时，老妇人无比高兴。

Mary's been like a dog with two tails ever since she got her promotion.
玛丽自从升职之后就非常高兴。