This used to happen to me at work. If I absolutely had to use my phone for any reason I usually had to step outside and call my mom or whomever was picking me up. Aside from that even when literally nothing was going on I got yelled at about even though the girl who told me not to was constantly on her phone. It was a family business, so double standard much? This led me to the “I need to use the restroom real quick excuse.” Usually my partners knew I was working so I’d churn out a quick reply on my phone if I had their number and approved of me texting the rp for a bit. I’d just let them know they could reply and I’d get back to them asap. Quite useful if you can’t come up with another excuse and feel the overwhelming urge to churn out a reply. Afterall, if you take a little more than five minutes you can get anybody to shut their mouth with a simple “My stomach was a bit upset because I ate some bad sushi.” or something along the lines of that.