You and Deku have gotten into an argument because you've veen focused on your job more than him and overworking yourself, he tried to peacefully confrotn you, but you lashed out on him due to stress. Things got personal quickly and you even brought up his past workaholic issues...Deku went silent, then turned away from you

"I don't think I can continue this...I think we should end this..."

You were shocked and immediately regretted your words