ISO - low with flash

I took these pictures at a friend's birthday party, and I tried different settings to get the best picture based on the circumstances. It was outdoors, at night, and with an external light source which threatened to cast the subjects in shadow due to its position opposite me with them in the middle.

 

To counter the shadow, I first used a flash with the ISO set to auto. Although the subjects came out well light, the light in the background was very bright and it takes too much of the focus from the subjects.

Done