Cut bacon into thin strips and fry them crispy in a large sauté pan. Remove them from the pan and place them on absorbent paper, keep the fat in the pan. Sauté onions and garlic over medium heat in the fat from the bacon. They should not brown, just become translucent. Add white wine and let it reduce - it takes 5 minutes. Turn off the heat when the white wine has evaporated. Whisk the eggs together in a bowl with parmesan, cream, vinegar, lemon juice, and pepper. Set aside. Cook your spaghetti according to the package instructions, but cook them 1 minute less, as they will finish cooking in the sauce afterwards. Drain your spaghetti but keep about 1 dl, as the starch will help thicken the sauce. Add the spaghetti and egg mixture to the pan with onions, garlic, and the white wine reduction. Toss the sauce together and add the cooking water from the spaghetti. Continue to toss the pasta until it has absorbed the sauce. Once it looks good, add bacon and a bit more freshly grated parmesan and freshly ground pepper.