She has a really good point. People working so closely and then get into a relationship, if things go bad, then there's the danger of power-play moves being used to hurt the other party.
At the same time, he can't just pretend his emotions aren't there, especially as these are the first time he's experiencing such emotions.
If they are going into this relationship, they NEED to actually consider it carefully.
But I praise our ML for actually having the courage to come forward with his feelings. It took a while, but he's able to recognize that things can't be the same and they have to work out their feelings, and he wants to pursue it. It could end badly, but he doesn't want to reject his emotions.