Don't fret. It happens to everyone at some point. A few years ago before my boyfriend and I lived together he shared a place with his brother and his girlfriend and their 4 kids, and they dominated all 3 bedrooms when they moved in with him. My boyfriend slept on the couch. Needless to say we didn't get a lot of privacy. Typically once it got late we could get away with doing whatever on the couch but I get paranoid about getting caught so most of the time we would just take it to the bathroom. One night around 9 or 10 pm he was itching for a bj and despite my paranoia, I figured everyone was asleep so I went to town. Within a couple of minutes the oldest daughter, I think she was 11 at the time, walked into the living room and saw everything. She darted back to her room and I was mortified. My boyfriend ended up telling his brother the next day what happened so they didn't have to hear it from her if she decided to say something. He apologized profusely. His brother just laughed and shrugged it off and said their kids walk in on them fucking all the time. No one their had locks on their door anyway. It's just life. Sometimes you get caught with a dick in your mouth.