Lance would never let Keith live it down. Being your brother, Lance was not too fond of Keith. For more than just the flight school issue, actually. See, Keith had a crush on you, and Lance hated every second of it. But under all the over-protective-brother emotions, Lance shipped you too. So when Keith had to ask Lance's permission to ask you out, he decided to prank him a little bit by pretending that he wouldn't allow it.
•••
"I'm just kidding, Keith."
"Oh- Lance I swear, I'll get you one day. You had me worried there."
"No, go for it Keith. I can tell they honestly like you. Just don't break their heart or I'll kill you."