why is the mother so weird?

Hey, my mom is almost 40, and lately she's been complaining about us (12, 14, and 16). My dad doesn't live here, and the apartment is too small.

At the weekend her boyfriend comes over and she often sends us out because they want some peace and quiet.

She used to be extremely patient, but not anymore, even though we all help out around the apartment and I always clean the bathroom, for example.

She often snaps at me when I come home from school, and so do the others. We don't do anything differently than before.

when I ask she says it's nothing or something

and in the morning when the boyfriend was there she was even weirder

In the bathroom, she once threw some cut condoms into the trash. It was so weird, and her boyfriend usually stayed for two days, and now he's only coming for one more night.

What does all this point to? And don't say, ask her because she doesn't want to say anything.

Do I have to move out? Am I allowed to do that at 14?