To all...

You do not need to lie.
Just say something that is truth...... You have every right to not go to any social event.
You have your own life, make your own decisions.

Just say, "I'm not going." "I won't be there."
if they ask why/why not... you can say, "I'm just not going."
The less you say, the less argument they have.

You don't need to lie when you're making your own choices.