Margarita Cupcakes With Lime Buttercream Frosting

So, the title of this post totally suggests that these should be AWESOME. And I think if someone else had made them, they probably would be. I apparently did something wrong, but I'm not sure what. The frosting is good though!! Also, I did not use the recipe for the frosting that is listed - I was lazy and just added some lime juice to some Pillsbury buttercream frosting. As you can see from the picture, I tried to be fancy and pipe the icing on the cupcakes, because I kind of suck at frosting. Well, it didn't work out so well, so I ended up frosting most of them. Also, if you go the lazy route and want to pipe your frosting on - get two cans of it! I would've run out if I had piped frosting on all of them!

Ingredients:
1 package white cake mix
1 can (10 oz.) frozen margarita mix, thawed
3 eggs
2 tbsp. oil
1 tbsp. grated lime zest

Directions:
Preheat oven to 350 and line muffin cups with those little muffin cup thingies

Combine everything but the lime zest with a mixer, then stir in lime zest.

Fill muffin cups 2/3 of the way full and bake 22-24 minutes.

Let cool before frosting.

Frosting Ingredients:
4 c. powdered sugar
1 stick unsalted butter at room temp
1/8 tsp. salt
3 tbsp. lime juice

Frosting Directions:
Mix everything with a mixer until fluffy

Cupcake source: http://www.cupcakefun.com/
Frosting source: http://www.jasonandshawnda.com/