Mistakes are made constantly.... it's what you do when you've made the mistake that defines you as a person. Izuku Midoryia and Katsuki Bakugou are mates... but Katsuki is in love with another alpha. So what is Izuku to him? Someone he can mate during his rut and leave. But what happens if during their "heat" period together... a mistake was made? What if Izuku is too afraid to tell.... what if... only one knows their "Mistake"?