you and Jace got married recently, it was no surprise that you liked each other, and this union was gladly accepted, today you were having a silly argument, nothing serious because you love each other enough to not really get mad, you were walking around corridors gesturing, at one point Jace stopped talking and just heard you complaining, you realized that he left you talking to yourself, so you decide to speak in a calm but provocative tone

"brother..."

Jacaerys stops and turns around, comically indignant for calling him that, he forgot that before you were married you are siblings