TIFU by walking on my friends parents and then having them walk in on me

My friend Anna is from Brazil and moved to the US for college and lives/works here now. We are both in our early 30s. Her parents were having their 25th wedding anniversary last weekend. She knew I had expiring PTOs and invited me visit Brazil and stray with them for a few days. I did few days with them and few days solo.

We got to their town at 4 AM, took a small nap and they had a day planned. Family beach day and then backyard bbq. We went to the beach at 10 AM and it was a culture shock. Anna’s mom was in one piece thong, she had a tattoo on one of her cheek, she was beautiful. Her dad wore a shorts that most men on the beach did, it was between a boxer brief and a speedo. There was nothing left for imagination.They were really hot 56 year olds. They are professors at a university, I did not expect that. Anna and her brother gf also a thong swimsuit which I was not surprised with since I have to be the beach with her. I just wasn’t expecting her parents to be that open infront of their kids. There was nothing creepy happening. Just me not expecting that is all. Her mom and dad were on my all all day.

We came home, had the bbq that ended at 10 pm with some of their friends. Some of Anna friends, her brother, his gf decided to go to a club after mid night. I was too tired from flights and the day and since I am usually going back home from a club might I did not feel like going so I stayed back. Here is where my tifu begins.

In the chaos of all that her parents did not know I was staying back. Her parents room was on second floor, Anna was on third right above. I had a mezzanine floor in the third floor in the back since me and Anna are not great at sharing bed space. I left my suitcase in Anna’s room. I went to kicthen in the first/ground floor to fill water and with my tired brain walked in her parents room in the second floor. They were fucking..on their anniversary. Her dad was fucking her in missionary and she was shoving a vibrator dildo up his ass. I froze for a sec, said. “Oh sorry I am in the wrong floor…enjoy the anniversary sex” and went back. Seeing them naked and fucking turned me on and 20 mins later I decided to masturbate. I was head phones on and their parents came to talk to me (mezzanine no door). They apologize and went down. They were in the dining kitchen so I went down after….tired, sleep deprived, horny and still edging. I said “sorry I was pleasuring myself on your couch..but if it makes any difference I was turned on by you guys and thought about you”. Then profusely apologized. I tried to sleep all night but did not sleep.Later on, Anna’s mom told Anna (apparently anna already knew her parents engage in ass play) and Anna is making fun of me now.

TL;DR: Visited friend parents anni weekend, TIFU by walking in on them, then they walking on me and telling them I was thinking of them.