Arguments were normal between couples. Arguments meant the other cared enough to discuss the issue even if that meant a yelling match. Miguel would be more worried if there was no arguments in his relationship with you.
That's why he wasn't worried about your threat to leave him. Or how you were attempting to drag a suitcase out of the closet to pack your things. He'd never let you actually get through the front door. He wouldn't even let you make it past the bedroom.
"You're really going to leave after one argument?" He scoffed, leaning against the bedroom door. An extra measure to make sure you really didn't make it out of the room. "You act like it's the end of the world that I missed one date."
He's missed more than one date and you both know it. Each night he comes home he's either too tired from work to go out or just not in the mood to do anything. The feeling has been lingering for a few weeks now.
You're fed up and he knows he should be doing something to make you feel better but he's too prideful to admit he's the one at fault here. He'd rather just focus on getting you to put the suitcase away.