There are a several inappropriate things I have done that still haunt me although none were done with malicious intent. Details concealed to protect the other parties. If any of them read this I give my apologies and want the relevant people to know that I regret these actions and hope that they didn't have significant impacts on them.
I once (well over 10 years ago) squeezed the leg of a woman who was a passenger in my car. It was not intended sexually and I hope she understood that after I apologised immediately and profusely. I was driving and I can't (and couldn't even at the time) remember what I was thinking as I did it but I remember the exact location and my immediate reaction of horror and embarrassment afterwards. It is an action I had done with girlfriends, as an act of affection and support and I think it was an action of essentially autopilot that was highly wrong and inappropriate when the person in the passenger seat wasn't in a close relationship with me. I recognise that a deliberate abuser may have acted the same way including the apology and it may have made the woman more nervous and risk averse and I deeply regret doing it.
Even further back I had a close friendship with someone who was fairly troubled. I had strong feelings for her and wanted to save her, I had naive and foolish thoughts that a relationship with me could help. We did have sex several times, (foolish dreams that if I could perform well enough she would love me and I could save her) and looking back I do worry about whether on all these occasions she was sufficiently sober to give proper consent. In no way was I trying to get her drunk and I don't think I put pressure on her but looking back there are better ways I could have acted.
At the very start of secondary school there was girl who we (at least the boys, maybe the girls too) perceived to be a mean bully. My recollection of what she actually did is faint but as I remember the emotions of the situation I recall meanness and verbal bullying (I have a slight fear that she was just assertive strong person which would make me even more embarrassed and regretful but even if the perception was correct the response was deeply wrong). I'm not sure whose idea it was or who started it but the response boys in the class struck on, being unable to resolve it with violence, was to pinch her bottom in which I regretfully participated at least once. At the time I was immature and I didn't understand and wasn't even aware of the sexual aspect of this and just thought it was nuisance that was annoying her back (for whatever wrongs I perceived at the time) and didn't think it was a serious or major issue. That this was happening was reported to the teacher and we had a severe telling off and the seriousness of this sexual harassment was explained and it ended there. I can't remember if I apologised at any point. My view of the seriousness and potential impact of what we did has grown over time, and my doubts as to whether the meanness I was clumsily and inappropriately responding to even really existed have grown. My only defence here really is that I was 11 and really didn't know what I was doing.