How it happened
in my head
Gendry snaps at Arya in reaction to the unexpected jealously and protectiveness he feels when she says she needs Jaqen’s help, not his. Arya is extremely hurt by his sudden outburst (even though she tries to hide it) and proceeds to ignore him because she never expected Gendry, out of all people, to treat her like that. Gendry feels unbearably guilty and tries to make it up to her and finally, four days and multiple failed attempts later, he finally earns her forgiveness after he gives her half of the fresh, just baked loaf of bread that he stole from the kitchen.