In the fourth season, Alex and Charlie are revealed to be hanging out with Tyler a lot, as Charlie points out in Justin's Welcome Back Party that they were spending almost every night at Tyler's together. On the camping trip, when Alex approaches Zach and Charlie's tent. Alex tells Charlie that Zach had told him he could bunk with them, which Charlie is fine with. Charlie asks Alex about Winston, implying that he knows they had a romantic relationship. Alex asks Charlie what he knows, to which Charlie tells him that all he knows is that Alex is a good person, and he's sorry if Alex feels bad.


Charlie finds Alex hiding in "House Party".

Charlie informs Alex that the House Party got cancelled, which Alex does not care for but asks what a "Find Your Drink Party' is. Charlie answers his question but says that he doesn't 'endorse traditions'. At the Find Your Drink Party, watching some old movies together. Charlie and Alex get high after eating some weed cookies Charlie made. They talk about how Charlie's learnt to make the cookies. Charlie reveals about his mother's death.


Charlie helps Alex during his panic attack, in "Thursday".

They're next seen together in a school lockdown drill under the table together with Tony Padilla. Alex begins to have a panic attack and Charlie tries to talk him through it, holding his hand. Shortly after, Alex starts insisting that he hears his dad and stands up. Charlie manages to get Alex back under the table, saying that his dad isn't out there and his mind is just making him think that because of his traumatic brain injury. After the lockdown is over, Charlie reveals to Alex that he looked up information about traumatic brain injuries to understand what Alex was going through, and kisses him. Alex tells him that it surprised him, but then kisses him back.


Charlie trying to talk to Alex at class, in "College Interview".

Charlie is shown to be following Alex constantly and believes they're a "thing" now, but Alex gets annoyed and tells him to stay away from him. Charlie later finds Alex at the pier, where he tells Alex that he's breaking his heart. Alex wonders why Charlie even likes him as he's not a good person, but Charlie tells him that he has an excellence taste. Before Alex leaves, he tells Charlie that they're never going to be together and as Charlie is not going to give up on him, he's going to walk away.

During The Student Riot, Zach questions Alex on why he's with him and not Charlie. As Alex runs outside, he finds Charlie unconscious on the ground and attempts to drag him away when a nearby car explodes.


Charlie and Alex talking the morning after they spent the night together, in "Prom".

About a week later, Charlie stayed the night at Alex's house. The next morning, they mention that they liked sleeping next to each other and that someday they can do more than just sleeping. Alex sneaks Charlie out of his bedroom so his parents don't find out. After they and their friends decide to start opening up to their parents, Alex invites Charlie over for dinner and introduces him to his family as his boyfriend. Charlie is happily greeted by Alex's family, especially his brother Peter as he's excited that Alex is dating a quarterback of the football team. Alex's mother talks to Alex and asks if Charlie makes him happy, which Alex confirms. His mother hugs him at this reply. Charlie also comes out to his dad as bisexual and mentions that he has a boyfriend.


Charlie's Promposal to Alex in "Prom".

In the next few days, Charlie attempts to ask Alex to prom. At first, Charlie puts on banners and waits for Alex with balloons and roses, but Alex ignores him. The second time Charlie asks Alex to prom, the whole class helped him by wearing a cardboard cut-out of Charlie's face and a sign that says "prom?". Unfortunately for Charlie, Alex thinks it's creepy and walks out of the classroom. The third time Charlie asks Alex to prom is in a small room, where Alex finds Charlie and a bunch of lights that say "prom?." Alex finally agrees to go to prom with him, on the condition that Charlie would stop with all his attempts.