I've repeatedly sat in a rooms of professionals @XChrome @InevitableNameChanger and discussed abusive behaviour. What it looks like all its forms. How lightly the term is now bandied around, meaning its seriousness of action and response has weakened. How anything which is slightly adrenalin raising for another is considered abuse by someone. How the black and white abusive actions we can all agree on has been coloured by people extending what the grey area around them looks like.
No, the abused person doesn't always get to define the word, as some people will say they've been abused, e.g.because someone has (rightly) said no to them. Again, something which has been interesting to discuss with professionals.
If the marriage was celibate, which you so often read about on here, then the cheated on partner's physical health is not at risk. By some people's definitions, including some of the posts here, this means the affair is not abusive. Others will say it is abusive, as the emotional health of the cheated on partner has been damaged. It could be argued that the emotional health of the cheater had been damaged long before they cheated, as their partner unilaterally decided to remove sex from their marriage. It really isn't black and white.
By some people's definitions, everybody has been abused at least once in their life. My definition of abuse does not agree with theirs.
So, like I started with, I'll continue to disagree with you that lying is abusive. The consequences of that lie may be abusive. A marriage partner lying that they are monogamous is a lie, nothing more.
Anyway, I'm bowing out. I've got a Taylor Swift concert to get ready for and I cannot tell you how much excitement there is in this house. Typing this out has made me recall a post on a US forum branding Ticketmaster as abusive. This was due to some people being allowed to buy tickets for multiple nights by their system, meaning the real TS fans chatting on the forum couldn't get hold of any. Their mental health couldn't cope with how unfair the system was and they were suffering. There were several posts agreeing with the OP and a few telling them they were ridiculous. The few got shouted down, as they had no right to tell the several they weren't being abused by Ticketmaster. They were victims, don't you know?
Have a sparkly day everyone. I know I will.