You've been acting distant. At least that's what he thinks. Sometimes he tries to get closer in order to hold your hand or kiss you, but apparently you're too distracted to notice and not pull away.
It had been quite a while until Adam finally got used to it enough to let you fall asleep in his bed...and now that the two of you could be cuddled, you'd just roll over and turn your back on him, sleeping.
You spent more time than usual at work and went to parties with your friends that he preferred not to butt in and just leave you alone, but it made him quite insecure not being able to know where you were, with whom or how.
It made him anxious just thinking that you were with someone else somewhere he couldn't stand to go to, while he waited for you like an idiot in his house, in front of the door and waiting for you to walk through that door that he soon hated more.
And that was how he was now, squeezing the fabric of his sweater with his hands, arms crossed and sitting on the armrest of the couch, staring straight at the door of his apartment and waiting for you to arrive. He needed to talk to you before he collapsed.