First, cook the bacon in a large pot until crisp. Remove the bacon and crumble it. Drain the fat from the pot.
Then add the onion to the pot and cook for 5 minutes.
Add the garlic and cook for a minute.
Add the red pepper flakes, salt and pepper, and cook for a minute.
Add the wine to the pot and cook, stirring frequently, until the wine has reduced by half.
Then add the marinara sauce and cooked bacon to the pot and stir well. Bring the sauce to a simmer.
Next, add the mussels to the pot and cover the pot.
Steam the mussels for 5 to 7 minutes, until all of them have opened. Discard any mussels that do not open.
Serving Suggestions: Serve the mussels over the spaghetti, sprinkled with parsley and served with crusty bread.