My younger sister has just got engaged, and I’m really happy for her and her partner. The difficulty is, I’m not sure I can go to her wedding, which is still some way off. I love my sister dearly and want to celebrate her big day with her, but we have different fathers – and I can’t stand hers.

Her father, who is my stepdad, was often emotionally – and occasionally physically – abusive to me when I was growing up. He was also frequently bullying, controlling and violent towards my mum, to the extent that he destroyed her confidence and hospitalised her. I believe in forgiveness, but he has never taken responsibility for his behaviour, and always lied about it. My mum died several years ago, and he has gone on to be abusive and violent to other women; he has always denied it or blamed other people for his vile behaviour. As far as I’m aware, my sister doesn’t know the truth; she seems to believe her father’s story, that he’s a victim of a police conspiracy when he is repeatedly arrested. I have made it my policy not to bad-mouth him unless she directly asks why we don’t get on – and she never has.

I am both scared of my stepdad and furious with him, and have gone to great lengths to avoid him in recent years as I’m sure it re-traumatises me. I will feel so guilty if I don’t go to my sister’s wedding, and I think she would be upset, but I’m worried that if I go, I will be extremely distressed and unable to pull myself together. What should I do?

I’m so sorry to hear about what happened to you and your mum. You have a few options, which include not going to the wedding. Part of me thinks, why should he stop you going? But I also understand how difficult this is for you. It might also be highly triggering, and I think that’s something you can understand only when you have been a victim of violence.

While I admire your stance of never bad-mouthing your stepdad, I wonder if now – with the wedding some way off – is the time to talk to your sister with a bit more transparency and honesty. You don’t need to go into detail unless she asks, but you could explain your position. I imagine your sister is aware of her father’s abusive behaviour, because he has so much previous form, but she may be in denial. Your truth might not be hers and she may not take kindly to being told what her father was like. But that doesn’t mean you can’t start a dialogue to say how you feel, which is harder for her to deny.

So option one is to open the conversation gently and thank her for the invitation, but say you don’t feel you can go because of everything that happened between your stepdad, your mum and you. This would leave the way open for her to ask for more information if she wants to. And she might not. Start the conversation with “I” statements. Even though your stepfather’s behaviour is his to own, it’s the way you feel that counts, and it will make the conversation less potentially contentious.

Option two is to say you would like to come, but feel worried about being in close proximity to your stepdad; you could seek some reassurance from her regarding, say, seating plans. If the wedding is likely to happen after Covid restrictions are lifted, it might be a big affair, which would make it easier to avoid him. You don’t need to get into everything your stepfather has done: this wouldn’t be to deny what happened, but to preserve your relationship with your sister.

If you do decide to go (whether or not you say something about your stepdad), would it be possible to go with someone who makes you feel really safe?

I’m not surprised that having contact with your stepfather re-traumatises you, which is why you should feel no shame or guilt in turning down the invitation if you decide it’s all too much. There is strength in knowing what you won’t put up with. If this does end up being your preferred option, then say no early (make an excuse if you have to). But also be clear that you really love your sister and would like to celebrate her big day some other way, at another time: put something in the diary.

If it were me, and I could control (as much as possible) my immediate environment and make myself as safe as I could, I would go. I think your stepdad has taken too much away from you to let him dictate any more.

• Every week Annalisa Barbieri addresses a family-related problem sent in by a reader. If you would like advice from Annalisa on a family matter, please send your problem to ask.annalisa@theguardian.com. Annalisa regrets she cannot enter into personal correspondence. Submissions are subject to our terms and conditions: see gu.com/letters-terms.

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