“Sinful” means “Missing the Mark” of what we are about as Catholics; we are made Catholic to offer Sacrifice with Jesus. He said that night, “I have desired with Great Desire to eat this Passover with you.” He did not say, “I have desired to eat this Passover by myself, nor with just some of you.”
We sacrifice the passover with him, the Last Supper; we are literally taking part in that night with him, that night is “Re-Present”. We do not commune weekly; we commune One Time, always Re-Present on that one night with him. We cannot afford to miss the Mass for which we were made Catholic, we were made his Disciples who watch with him, eat with him, die with him, rise with him. If your appearance bothered him, he would not have allowed his servants to grant you confirmation and the Holy Spirit. But since he gave you his Spirit you must do this.