Some ponies are just naturally better then others when it comes to keeping secrets.
When you have a secret like Crimsons however you start learning to be good at keeping them, even if you weren't already.
Only few even notice that he is hiding something in the first place, and even fewer manage to find out what it is.
When he meets Ves one night however, he thinks that he found one individual whom he might be wiling to tell his biggest secret