Lucifer would catch in the corner of his eye, Adam going for one of his daughter's best friends. He couldn't let someone like Adam hurt more poeple. Nevermind someone close to his daughter

Lucifer would block Adam and knock the swing out of the way with one wing, getting the person to safety and rolling his sleeves up ready to fight Adam

afterwards lucifer would walk to where he put the person,holding out a hand and questioning "you aren't hurt right? You don't look hurt...but"