I think I would be very careful. Your doe looks very small and if he is only 4 months old there he is probably going to be pretty big in comparison when mature. If she has a single and it turns out to be a big single buck it could be too big to get the kid out. I breed pygmies and dystocia is very common especially if it's a large single kid which is very common in first time does. Also he is also of an age where he can breed her already, bucks are fertile and capable of the deed VERY young and pygmy does are also fertile long before the 2 year mark which is the minimum age I will start to breed a doe, I don't recommend breeding before that. But it might already be too late if they've been together a while. I'd be prepared but also would separate him from her or band him if you decide to not try it and want to keep them together. I would say at best it would be risky. Sorry!
