Using the phone on the bus

[rebbonk]

I had just hung up my phone on the bus this morning when I got a tap on the shoulder.

"Excuse me," said a teenage girl dressed in her school uniform. "I wonder if you could settle an argument for us? Me and my friend just overheard your phone ringing just then and I'm pretty sure it was Beyoncé, but my friend is adamant it was Rihanna..."

I said, "You're both wrong,

Spoiler:

it was my mum."