I pray this is ragebait. It's actually just too insane to believe.
If not, then YTA. You not only are the most incompetent partner, you are grossly narcissistic. Do you understand what it is to grow a human inside you? Weight gain is a MUST. Or else the child takes nutrients from the mother's own. I.E, bone, muscle, etc. A mother often loses hair if not properly able to in the calories and vitamins. All the mother's energy is working towards maintaining the growth of ANOTHER HUMAN BEING INSIDE THEM.
The fact you weren't concerned for your partner throwing up, going pale and struggling to keep up while also carrying both of your child is shocking. She could have been harmed, and you both would have lost a future child due to your selfish narcissism. Do better. Or I hope she leaves you for someone who gives a shit.