I do have the Ibex boy shorts to wear when x country skiing or snow shoeing. Before I had them, I just wore my silk long underwear between me and my wool tights or hiking pants. The problem came when doing winter sports in sub 20 degree temperatures, or hiking in cool, but not cold weather. I needed warmth to "cover my butt."
However, the boy shorts ride up terribly, effectively giving me a wedgie. I tried going up a size, but it's still horrible. They are just not cut for someone built like me. But, I deal with it, to avoid being cold.