Cut each snow peas in half crosswise, on the diagonal.
Heat the butter in a large skillet over medium-high heat until just melted. Add the sugar snap peas and stir-fry 1 minute. Add the soy sauce and the lemon juice and bring to a simmer, stirring, until the liquid reduces to a thin glaze. Cook, stirring, until the peas are tender but still crisp, about 2 minutes. Season with the pepper and serve.