Okay, so it's not terribly exciting, and it was only a dribble but I desperately wanted to share the news with someone
I've been trying to put him off potty training as he's still quite young (was 2 in May) and I still remember potty training his brother, lol, but ds2 keeps wanting to try (presumably copying his brother) so we put him in pull ups and only bother putting him on the toilet if he actually asks.
Bless him, I'm really chuffed.