soft/weak in the head
头脑不清楚
A:If you fall in love like him, you will go soft in the head, as well.
A:如果你像他一样坠入情网,你也会颠三倒四的。
B:Come of it!
B:别胡诌了!
A:You want a bet?
A:你敢打赌吗?
B:Why not!
B:为什么不敢?