In keeping with his general attitude, George tries to keep his engagement to Amelia on the down low from his fellow soldiers. Instead, he acts like a womanizer, and the other soldiers (who are really just teenagers still) don't realize that he's a poser and admire him.
Only Dobbin is sort of scandalized by the way George treats Amelia. Um, because he's in love with her himself, maybe? Dobbin tells the barracks that George is engaged to a wonderful lady, then makes George go visit her.
George borrows some money to buy Amelia a present, but on the way he sees a diamond pin that he likes and buys it for himself instead.
Still, he does finally go see Amelia, and they have a very nice day of "building numberless castles in the air" (13.30) about their future lives together. She wants a nice house and family. He is mostly obsessed with making sure they live appropriately to their social status.
The two then go to dinner at George's house. We meet his father, a very rich merchant who is in a bad mood.
Afterward the women leave the room.
OK, a little aside here. In Victorian times, after dinner the women would go off and have girl-time for an hour or so while the men had man-time. Then the men would rejoin the women for drinks, music, and maybe cards.
Anyhow, after the women leave the room, Mr. Osborne tells George that Amelia's father has made some terrible investments and might be broke. This means the engagement between George and Amelia has to be called off.
George is all huffy and offended, since breaking the engagement would be dishonorable, and he really prides himself on his honor. (Really, though, what doesn't he pride himself on?)
Amelia can sense that something is wrong, mostly because George is suddenly much nicer to her than usual for the rest of the evening.
The next day, when George picks up his allowance from his father's bank, he sees Mr. Sedley (Amelia's dad) looking pretty grim.