Maybe your first boyfriend abused you.

或许你的第一个男朋友虐待过你。

youdao

People have the first boyfriend or girlfriend?

他们才有第一个男朋友或女朋友？

youdao

Her first boyfriend had drowned in a lake after driving a car into it.

她的第一个男朋友把车开进湖里淹死了。

youdao

She became involved in prostitution at the insistence of a former boyfriend, who beat her,and forced her to sell her body the first night they arrived.

VOA: standard.2010.02.23

The first example I can think of is if, let's say your boyfriend or girlfriend has just acted outrageously.

我想到的第一个例子是，假设你的男友或女友突然表现得很蛮横。

I can't help but 课堂 - SpeakingMax英语口语达人

And then, when I had my first boyfriend, I realized maybe it's not for me.

CNN: For Better Or For Worse

Within the first month of going raw, she had her first boyfriend in more than five years.

CNN: Woman goes raw, loses more than half herself

She had come to a point in her life of getting through her low self-esteem and was happy in having her first boyfriend.

BBC: NEWS | UK | Scotland | 'My little mentor lives always'