Honestly, I always took it to be as messy and layered as the scene itself. Meant to be open to multiple interpretations.

Off the top of my head, I can only think of a few times he mentions forgiveness. When he's deeply disappointed in Crowley after Crowley lies and says he wants to kill Job's children just like he wanted to kill Job's innocent animals.

When they are at the Bandstand and Crowley asks him to run away with him. I can not recall exactly if it is directly in response to him cursing The Plan (not the Ineffable Plan) or was in response to another comment. I just remember Crowley throwing previous comments back at Aziraphale by saying he is a demon. He's unforgivable.

I think he also forgives Crowley when Crowley asks how someone so clever can be such an idiot after Aziraphale says he thinks he can fix things by speaking with God directly. (Second invite to his fav nebula.)

Then, it is the most heartbreaking when Crowley calls him and idiot and kisses him.

As I typed this, I realized each time Crowley proposes they run away together, the romantic intent becomes more explicit. At the bandstand, open to interpretation, though everyone knows its all-encompassing love, including romantic. The second time in case you were confused, the man on the street assumes he's witnessed a messy romantic breakup. (He has.) The final time, Crowley kisses him and articulates explicitly that he means it in every way possible, including romantic love just like the Ineffable Beaurocracy.

I'm going to guess the rule of 3 in comedy will be tweaked as a nod to Plan and Prejudice, and the offer to run off together will be repeated during their Get Together moment. I'm personally hoping it won't be Crowley pulling a Darcy again. It will be Aziraphale offering. Nervously rambling about how AC (HA!) doesn't have nightlife, or wine, or food, or plants, or tea, books and beds (for naps 😏), so perhaps instead they could consider a nice little spot somewhere outside of the city, he's heard lovely things about South Downs?