I showered with my girlfriends mum

Nothing sexual happened. But this was so awkward and idk how to even mention it to my girlfriend. I m20 woke up late at my girlfriend’s parents house, she’d already gone to work and not woke me up. I looked at the time I had half an hour before I had to be at work. I ran to the bathroom started my shower. Their bathrooms don’t have locks anymore because someone got locked in once and they had to call the fire service. I got 5 minutes into my shower before her mum bursts in. I shout I’m here I’m here. She just says sorry pet I’m running late for work look away. It’s was extremely awkward and close. I was done in 2 minutes after that and ran to work. I haven’t spoken to my girlfriend or her mum about it since. Do I even bring it up or should I take it to the grave?