Cook the bacon until crisp and drain well.
Cook the pasta according to the directions on the package. Drain and rinse well with cold water.
While the bacon and pasta are cooking...
Add the mayonnaise, vinegar, tomatoes, green onions, salt, and pepper to a big bowl.
Stir well and add the bacon followed by the pasta.
Taste and adjust the seasoning.
Serve immediately or cover and chill.