What do I do about possible infidelity?

This is so difficult. I'm sorry you're going through it.

I would say that you should tell you mother that this is her business between her and your step-dad, and that you'd like to be kept out of it. That whatever she'd like to do to confront him with her concerns, she should do. You are not her partner, or her confidant. You are her child. Establish some boundaries there, or otherwise it will open doors for you to be involved in their disputes from now on. Also, if your step-dad ends up without fault in this (perhaps he is doing something else that he doesn't want to be found out about, or maybe he has specific reasons for deleting the footage that would be justified), if so, he won't trust you again. Boundaries are necessary here. Call your mom, and tell her that you won't be used to spy on your step-dad, and that she should confront him herself. I know this is difficult because you've already been involved, and you care about your mom and your step-dad. However, this is honestly not your responsibility. Free yourself of it, and put it back into their hands.

I hope you have peace and clarity as you choose your next steps.

 

I'm so sorry you are going through this! That sounds like a lot of pressure put on your shoulders, not to mention all the emotions and worries.
Most importantly, please remind yourself that your parents are responsible for their relationship and that it is not yours to deal with. It's okay not to get involved and okay to set a boundary here if you wish to.

They are playing that "outsmart the other" game.
The part of the relationship you describe here between them is based on both avoiding to talk and share information, and everyone is doing that in their own way with you in the middle of it.

You can if you want tell your stepdad and your mother that they need to evaluate their situation together, whether he is having an affair or not (some people do weird things just to have a moment for themselves that they don't like to talk about. But maybe it is an affair, then the damage was already done before that and the affair is more likely a symptom for something bigger that they really need to adress.) Things will just boil up even more if your stepdad keeps believing that omitting is going to keep the peace, and if your mother is keeping herself in a investigative (maybe slightly moving towards paranoid) state of mind. No place you want anyone to be in for too long!

I wish you a lot of strength and calmness in these difficult times, and that they solve this in the best way possible.

 

Okay, take a deep breath. If you are still feeling extremely anxious, that's alright. If you could take some time away from your house, it would do you good - your home is unfortunately a battleground right now and grounding yourself inside it won't be as easy. Take a short walk around town, and stop once in a while to rest your eyes. It may help.

So. Impact Character, Asa, and Anomaly have said exactly what I would say. I'll say it again for emphasis though: this isn't your fight. You're caught in the middle because they're trying to outmaneuver each other. Like Asa said, this to me sounds like there was preexisting problems in their relationship, and that's usually the case with infidelity.

They're both trusting you to a degree, though I sense that your mum has been in your life much longer. Your stepdad, not to be too blunt, sounds like an idiot.
You can wait to tell your mum after her road trip, but by the sounds of it it's already troubling her and I'm not sure it would make much difference. Would you know if the security camera company keeps backups of your footage? if so, that could be helpful, because right now it's your word that she'll be relying on, and your stepdad may resent you for that.
Otherwise Asa's right. Because you're the sole person with access to the footage, you'll have to speak with her about it sooner or later.

I'm sorry you're going through all this @Vaguethinker . I don't think it's fair or healthy for your parents to involve you like this, though unfortunately happens often.
What are your options? as somebody who grew up around similar issues, one of the most disconcerting things is feeling like we have no control over what happens. But to an extent, we do. We can make sure that we land on our feet. Like, do you have friends or extended family you could visit for a while, if you want to be away from home? Or if these games continue, what do you have that your dad or mum have access to or might want access to? like the laptop.
If these questions make you feel further overwhelmed, then you don't have to pursue them. For somebody like me, it gives me a sense of control over my situation. However they could easily work the other way.
In any case let us know how you are doing okay? you don't have to go through things alone hugs

 

What they said..you are not the truth police. This is their mess and they need to figure it out without using you..

 

The truth will set everyone free. Good luck.

 

It's really unfair to bring children, even grown children, into these intimate matters. It's not a healthy dynamic. I would also agree that staying with other friends or family at this time would be a good idea. Ideally, just finding a place of your own if possible.

 

I agree with the other posters here, it's not your business. Keep out of it. Sorry you're impacted by all of this.

 

I understand the pain of being forced into the situation. It's disorienting to be pulled into other's chaos. Your Mother deserves the truth, but it is your Step-Dad who should be the one to speak it, and it is your Mother who should be the one to request it of him. If there is anyone that could act as intermediary for their issue, maybe a professional or a close friend who would be objective, then maybe you could suggest this for your mom as a support to her. You can empathize without carrying the burden of their choices. You can still speak the truth in what you've found, shedding light on it for your Mother, and then place it in her hands for her to choose what she wants to do and if she wants to confront your Step-Dad. Perhaps, letting her know that you don't wish to be a part of it moving forward, but that you will be there for her regardless of her decisions. Ultimately, you can have peace in handing back responsibility where it belongs, and caring for yourself in setting that boundary. I hope you do.

Edited to add: I just saw that you've taken some of these steps. I admire you for your courage. As for your Step-Dad, he likely knows that you know, and is worried and trying to save face. If you are as close as you say, then perhaps you can discuss this with him, and tell him that you don't need details, but that you hope that he does the right thing in telling your mother the truth. Then, as you did with your mother, place the responsibility back into his hands and free yourself from it. If he tries to place blame, do not take it, restate the facts, restate that you no longer want part in it and that he needs to speak to your mother. I hope for strength as you process this.

 

I'm very sorry that you're in this position. It's not fair and it's not right and both parties need to be told that this isn't fair it isn't right this isn't my business.

 

You keep repeating that you don't feel comfortable with being not honest yourself. Please honor that. I believe you don't necessarily need to act if nothing was wrong but you also don't need to start a conversation about their issues or something concret as the camera either. You feel uncomfortable and you worry about your family and the impact on your siblings. That is not an unimportant matter, and I think mothers and fathers usually want to know something like this going on with their children. You can surely consider if that is an option for you while keeping in mind that by playing along you are technically taking care of your grown up father not the other way around. What I mean is: it's probably okay if you tell your parents, both, that you love them and that you want (if you want) to visit friends or family with your siblings if that is possible. Maybe your stepdad can drive you guys somewhere or so before your mom gets home? At least that would be a bit more on the responsible side by them, you know? Or maybe your mom has an idea if you share your feelings. Just thinking here.. they are probably very caught up in their own issues right now and might not see very clearly.

 

I hope everything worked out for you, Vaguethinker.