From the previous chapter!

. . .

Request from ZoeSpook which is 15 and the pairing is Laurence and Garroth, 15 is who proposes first. 

It depends on who isn't an idiot a tells everyone and who's sibling isn't at least slightly crying once they see the other one and know that their gonna get proposed to. So if Laurence were to propose which he probably wouldn't he'd be very secret about unlike Garroth who'd tell his mom, dad, younger brother, and even younger brother, and as you can tell the result. Anytime Zianna(If she's there apparently) or Zane would see Laurence at least for 5 seconds they'd slightly cry because honestly, this is a very emotional thing they know. Laurence would stand there confused on what happened, but eventually, he'd get it once the proposal happens.