I see my sister-in-law masturbating with a very thick dildo, having several orgasms and with a swollen pussy

This morning I woke up to loud moans, when I approached my sister-in-law I could see how she was breaking her pussy really well, she was squirting a lot and shaking with pleasure, she stuck a huge dildo in herself as thick and hard as her boyfriend's, I couldn't help it and when she went to class I looked for the dildo and stuck it in me hard too.