how to use overflow ellipsis after more than one line

I am making a previous comments type box, and would like to use overflow:
ellipsis to show that there is overflowing text.

It appears that I can only make the ellipsis work when I use white-space: nowrap,

but the problem by doing this is that, it restricts the text to one line.

.testimonial{
  border: 1px solid black;
  border-radius: 10px;
  width: 200px;
  height: 200px; 
}

.testimonial p{
  margin: 5px;
  overflow-y: hidden;
  text-overflow: ellipsis;
  height: 140px;
}

NB. I put the overflow properties in <p> as I need another paragraph to show up after the overflow;

This is how my code above appears;

code output

How can I make the ellipsis appear in this example?