Can you overfeed a newborn?

growbeangrow

We have 2w5d twins and they have different feeding habits. Our boy seems to be insatiable. I feel like he could eat ALL DAY LONG. Just now, I let him keep eating and he ended up downing 5 oz of breast milk. Should I have stopped him or is it okay to give him as much as he wants even if it doesn't seem like a reasonable amount?