No you did not commit a mortal sin. Because you are a minor, you are under the authority of your dad who is the head of your household. However, parents are not perfect although I’m sure most give it their best shot.
I don’t know how comfortable you are talking with your dad but if you had a pretty good relationship with him, you could’ve tried to inform your dad that you didn’t feel good passing out the beers. Your father might’ve either responded in your favor and let you off the hook or continued asking you to pass out the beers to his friends–but at least, you would’ve had the chance to have your say.
As a young Catholic and follower of Jesus, you will be called upon many times in your life to speak up for him. While it isn’t easy, the more you stand up for Jesus, the easier it gets. If you feel a strong prompting in your heart, know that the Holy Spirit is wanting you to speak out and that the Holy Spirit will not only give you the right words to say, but the courage to say them as well.
Jesus said he would not leave us alone, so he sent the Holy Spirit to help us. Most people don’t know that if they just call upon the Holy Spirit, he will come. The next time you’re not sure about a situation, ask the Holy Spirit (Holy Spirit, help me!) and wait and see if words come to mind or if you start feeling stronger in your spirit. Just know that, even if it looks like you’re alone, the Holy Spirit is always there waiting for you to call upon him
God Rocks