Mine loved Mandy but she took the piss

Mandy was great but in the first series she took the piss sometimes.
She owed so much rent to Matthew, had no intention of paying it but was out all the bloody time spending money.
Then when she found Matthew in her bed she made him forget all the rent she owed him, that's disgusting. Instead of pissing money on clothes and drink, why didn't she pay her pissing bills.