Mommas I need help!

What mommas can give me tips on keeping my children out of my bathroom/away from bathroom while I’m trying to potty?? Even if I lock the door, they sit outside talking to me or sticking things underneath. Today my toddler sat & complained that my poop stinks…..ummm yeah I’m taking a shit-go away & u won’t smell it. Three bathrooms & I can’t shit in peace. My husband thinks it’s hilarious, I don’t! I really miss the simpler times when I could take my time in the bathroom.