I am pretty sure my mom is having a sexual relationship with my grandfather (her father) and I don't know what the right thing to do is.

I just want to start off by saying that I'm super disturbed and might regret writing this, but I feel like I must get it out of my system. Even if I just save it in DRAFT and never post. It's been bubbling inside me, and I don't know what the hell to do about it. I am not asking for advice, but I do hope I will feel better after I write it down. I play it back in my head, and it does seem wild, but it's the truth, and it's laying heavy on me. I don't know how this sub works, but please be sensitive with whatever you have to say. I am on the brink.

So my grandmother died about eight months ago, and ever since, my mom has been going to visit her father much more often. Sometimes we all go together; our entire family, I mean, but as it's hard to align our schedules, most of the time she goes alone and sleeps over for a few days, usually the weekend.

In my head, he was one of the nicest men ever. That's why this hit me really hard and threw me into a panic attack, because it's like seeing someone really decent do something you'd never expect. My mom did cheat on my dad a few years ago, and they fought a lot, but they worked it out, and now they are doing just fine. So although I know she has done some "stuff" in the past, this was super disturbing for me, and I am honestly feeling sick even as I am writing this stuff, but I am hoping it will help me feel better to put it out there anonymously.

He lives in a suburb, two hours away from the city where we live. This September, I had finished with work and school for the month and had lots of free time, so I decided to surprise and visit him. I usually wouldn't go unannounced, but I knew he was alone and always eager to see me.

I don't live with my mom, so I didn't know whether she'd be there, but I was assuming she might since she has been at his place pretty much every second weekend ever since the funeral. So I used an Uber, which cost me a shitload. I was pretty tired but still wanted to make him feel good since he has been inviting me to stay there for a long time and I finally could spend some time with him.And of course, my mom was there when I arrived; she seemed surprised and happy, as was my grandpa. So we talked and watched some stuff together, just average family time. He has a nice place there, so we took some walks in the nature nearby; everything was pretty good.

We stayed for two nights. The only odd thing that happened was that in the middle of the first night, I heard like some weird grunting, but it didn't sound sexual at all; I just assumed it's some animal outside or something. I didn't make anything of it. I had completely forgotten about it. On the second night, I heard the same thing and immediately remembered that I had heard it the day before as well. So I got up to see what's up. I opened the window, and there was nothing out there, and even worse, I realized it was coming from inside the house, like the hallway.

Then, I realized that it was coming from my grandfather's room, and when I started listening more closely, I realized that it's actually very sexual, and it's just like an old man moaning like a creepy pervert. I didn't even think it was that disturbing, but I was pretty grossed out. I didn't really want to tell my mom about it, but I did find it kind of funny, like it was kind of TEA, if you know what I mean. I was like, maybe let me just wake her up and ask her if she has also heard anything, and maybe she'll discover it on her own when she wakes up and hears it instead of me having to tell her about it.But then SHE WAS NOT IN HER ROOM. I went to the bathroom, and she wasn't there. The house isn't huge, and there is no other place she could have been but inside his room. And why the hell would he be moaning with her in there if they were not doing something? There is no other explanation.My body literally went stiff, and tears started coming up immediately. I went back to the guest room and went to bed, weeping. I don't, for the love of me, understand if they were not worried or how they didn't think I could potentially wake up and hear them.

In the morning, it was very hard to act normally.

My mom and I left on Sunday at around 5 p.m., and everything was normal afterwards, but I can't shake this feeling that I should tell my dad. What if I am wrong, though? I have been having such a horrible time ever since, and I do my best to not have to meet up with my mom. I have only seen her once after this time, and I just tell them I'm really busy with my internship and stuff. I am so disturbed, and I hate that my family is like this.

I can't tell my friends cause they will surely be super grossed out by my family and I don't want that to happen, I can't tell my brother cause he's still 15 and doesn't deserve that to be done to him. The only person I can realistically tell this to is my dad but then what the hell will happen?

It honestly made me even start digging in my past to figure out if I have some repressed memories like maybe I knew all along? But absolutely not. I can't say that I have. I tried being honest with myself but NO NO NO NO. This is so disgusting and shocking to me and my body is prob just running on cortisol in the last months.

I do plan on going to therapy though.

EDIT: I just have to add that maybe I was too vague in my description but once I was an inch from the door of his room, I was pretty sure it was sex moaning. Sure he could have been in pain but you don't moan repeatedly as if you're having intercourse when you're in pain. It wasn't like a single moan, it was like rhythmic. I actually shudder explaining this but I feel like if I'm going to write all this, it should at least be clear that I am positive it wasn't groaning in pain.

And as for my mom being somewhere else, in her room, her phone was sitting on the bed and all of her clothes, as well as shoes, were thrown around in her room. She definitely hadn't snuck out. Why would she go out for a walk barefoot in the cold without a jacket and leave her phone randomly on her bed? This is why I can't bring myself to think that. It was also somewhere around 2AM.

EDIT NO2: I decided to confront my mom but not in an aggressive manner. I will just mention it casually and see how she reacts. Someone mentioned to see how her body language will be and I think that's a great idea. It's pretty scary but I feel like I'd regret not doing anything about this and leaving it simmer inside me. I thought of doing it over the phone cuz that feels safer but I think it needs to be in person so I can follow her reaction. I will just have to find a way to meet with her in a non noticeable manner cuz she must have noticed me avoiding meeting her in the past month. So straight up inviting her to meet and then mentioning that would be too on the nose.