head over heels in love 爱得神魂顚倒；深深堕入爱河之中；热恋中；深陷情网

【例句】
The girl fell head over heels in love with him.
姑娘完全深陷他的情网。

Well, it's not a compliment , I'm saying it from the bottom of my heart! It's obvious that he's head over heels in love with you.
好了，我不是在恭维你，我说的是真心话，显然他已经死心塌地地爱上了你。