Getting caught by fwb mom

Just a short story, and no she didn’t join in. We normally have Sex at my place, since I live in my parents basement, but at least once a month, we do it at her house. Her room is close to her parent’s room, so we try to be quiet. One day her Mom went out for an errand, and we were messing around in my her room, she was giving a blowjob, I was laying in the middle of the bed, and she was sideways, with her legs on the floor of the right side. Then all of a sudden I we see her mom, I froze for a second, while my fwb hid behind me, and her mom stared for about two or three second the ran in her room. I quickly closed the door, my fwb just laid face down on the bed for about 15 minutes. She was so embarrassed, she said: “I can’t believe my Mom saw me sucking your Dick, and to make things worse, I was naked.” I hate seeing her sad, so I tried cheering her up, by getting her Teddy Bear and pretend like it’s sucking her Tits, and tickling her. Her Mom probably forgot something, and we didn’t hear the door open, so after that we learned to close the door. Good thing her mim likes me. I know the story may have not been that interesting, I found it cool how her Mom walked in on us.