The kids get all of your affection
If you have children, it’s especially easy to just let the romance fade away. You’re not really in the mood to cuddle or kiss anyone when you get home, but you muster up the strength to give your children affection, because that’s important. And that’s it. That’s all you had left in the tank. When your partner wants some affection (or sex) you are tapped out and you just want to stare at the TV.