How soon after picking up first watch can I ask for my second piece?

[Fifteen]

Hi Guys, I’m picking up my first AP so I’m very new to the game. Im picking up my first ROO diver in a few days. It’s one of those watches I am happy with, but it was more of a backup watch to build that relationship. Super excited about it, but I already know ahead of time that it won’t be suitable for all occasions due to its size and massive presence.

Grail watch for me is a black 15500ST (or an equivalent newer model that has yet to be released). I’m wondering if it’s ok to mention or ask for the 15500st while I’m picking up the ROO? Or should I wait a few weeks or so after the dust settles to express interest again. Thanks in advance!