First reaction? Be happy for him. Someone on your crew watched how you operate and decided to bet on himself for his family. That's a reflection of the culture you built, even if it stings a little right now.
The real issue isn't that he started a business, it's that his weekend work is bleeding into hours he owes you. So separate the two: lead with support, then get clear on the expectation. When he's on your clock, he's all in. That's the line.
But here's where I'd lean in instead of clamp down. This guy is now an operator in your market. That's not automatically a threat. There's room to mentor him, send him overflow that isn't your sweet spot, or partner on jobs neither of you could land alone. The ones who win long term build networks, not walls.
Handle it with respect and you keep a good man in your corner either way.
