I can and will leave whenever I feel like it.

I have this even with friends and family...

I have to leave for an after work social event soon. This is my future...

I just don't go in the first place. Problem solvered.

I regret I have but one clichéd response to give

For the people that need to hear it:

You can leave, and you can tell them those exact words.

You just don't think your friends and family will understand, and don't ask yourself why you would care if they didn't care about your happiness.

"It would make Mum sad"