Why is に used with this verb?


I just read a manga where by context a girl broke up with her boyfriend. She
says this.

> 逃げられたの 彼氏に！！
>
> 仕事に入れ込みすぎだって

Why is 彼氏に used alongside the verb?




> 逃げられたの 彼氏に！！

As you've noticed, this is an inverted word order of:

> 彼氏に逃げられたの

逃げられた here is Suffering Passive (迷惑の受身), which is a kind of Indirect Passive
(間接受身).  
As you know, in passive sentences the agent (動作主) of the action is marked with
に. eg お母さんが私を褒める → 私がお母さん **に** 褒められる. Here the agent of 逃げる is 彼氏, hence:

彼氏が逃げた (active) _My boyfriend ran away._  
→ 彼氏 **に** 逃げられた (indirect passive) _My boyfriend ran away from me (which
affected me in some way). / My boyfriend up and left (on me)._

For more on Suffering Passive / Indirect Passive:

  * [How to interpret indirect passives?](https://japanese.stackexchange.com/q/15933/9831)
  * [私に言われても versus 私が言われても](https://japanese.stackexchange.com/q/54800/9831)




> 逃げられたの 彼氏に！！

As you've noticed, this is an inverted word order of:

> 彼氏に逃げられたの

逃げられた here is Suffering Passive (迷惑の受身), which is a kind of Indirect Passive
(間接受身).  
As you know, in passive sentences the agent (動作主) of the action is marked with
に. eg お母さんが私を褒める → 私がお母さん **に** 褒められる. Here the agent of 逃げる is 彼氏, hence:

彼氏が逃げた (active) _My boyfriend ran away._  
→ 彼氏 **に** 逃げられた (indirect passive) _My boyfriend ran away from me (which
affected me in some way). / My boyfriend up and left (on me)._

For more on Suffering Passive / Indirect Passive:

  * [How to interpret indirect passives?](https://japanese.stackexchange.com/q/15933/9831)
  * [私に言われても versus 私が言われても](https://japanese.stackexchange.com/q/54800/9831)

