Your wife appears to be pretty immature in the way she is looking at this. Minimization is a omnipresent feature of cheaters, but sometimes it is just lying, other times it reveals an immaturity which I find makes the lying even worse, and does not fill one with hope that the cheater can process and grow in a way that makes them safe - if you ever want to truly stay with them after betrayal.
She seems to be caught up in a straw-man argument of whether or not she had invited this sleazebag over - the second time - with the intent of fucking him. So that is an issue.
Back to her straw-man argument of her lying and saying that you want her to admit that "she wanted intercourse", all that can be characterized as is a stupid and childish line of reasoning.
Personally, as soon as a dick goes in somebodies' wife's mouth (or any other orifice) who is not her husband, I think the "sex line" is truly crossed.
Nothing happened that she didn't want to happen. So she is picking something further down the line to make what she did do (or will admit to at least), look better by comparison.
The truth of the matter is she was "open" to much more than pleasant conversation, or else his dick would have never found its way into her mouth.
I've been in settings with women who were "ready!", who were "open", and who it "wasn't gonna happen" with.
And when you are with a woman who it isn't going to happen with, it ain't gonna happen. So she was at least open to sucking dick.
How do we know this? Because she did it.
To be "open" doesn't mean she has to write on a piece of paper beforehand: Sucking dick, yes, vaginal sex, no. She set the conditions. After that, it just has to happen, with her consent.
And frankly, there is no way to be sure of what was said before she had this man over to your home, a second time after already crossing boundaries, no less.
She 100% for sure was between "ready!" and "open". Be certain of that.
***
I understand Bigger's comparison of "just browsing" the hardware store with no intention of buying anything and coming home with a table saw that costs a grand, but in truth, that is much more spur of the moment and whimsical. I don't agree with the comparison - you don't just "browse" with strange men.
I think a better comparison is if you drove down to your local hooker stroll, and engaged in some petting with a hooker. Then you went back a week later "Just to test yourself" and somehow found yourself getting blown by a hooker.
The point here, is that unlike browsing the store, there is no fathomable reason for you to be down at the hooker stroll other than to do things with hookers. Just your presence there is wildly inappropriate, and any idiot knows that.
Imagine this: 'Hey wife, I was down at hooker alley because I wanted to test myself". How absurd.
Similarly, there is no fathomable reason for your wife to find herself, nay, intentionally make arrangements, to be alone with this man, other than to take their activities further down the sexual road, assuming she didn't lie about how far they went the first time.
She is trying to spin this as something that wasn't intentional, and it was 100% intentional. She knew what she was doing the whole time. She even had time in-between sessions A and B to come to her senses. She didn't care.
She doesn't identify with the other cheaters she reads about? Bullshit. YOU ARE WHAT YOU DO. And that is all there is to it.
- Wives don't find themselves with men who are not their husband in settings where inappropriate sexual conduct is likely "by accident".
- Kissing and petting don't happen "by accident".
- Dicks don't find their ways into mouths "by accident".
The "perfect storm" happened because she created the perfect storm. Period.
She was not bewitched, charmed out of her pants, played, none of that. She did what she wanted to do.
Lots of people want to talk about "the whys". Well there it is: She wanted to.
I think at this early stage "the whats" are much more important, in order for you to decide whether you want to stay with this woman.
99% of cheaters would rather focus on the whys than the whats. There is a reason "why", because the whats are usually bad, really bad.
***
Are you having her write these things down? Cheaters love to change their words up after the fact: "I didn't say that", "I don't remember saying that", "I didn't mean that".
- Have your wife write down what she thought she was testing.
- Have you wife write down what she wanted to talk about with him.
- Have her write down what they actually talked about.
- Have her write about what they talked about just prior to the act, right before the conversation stopped and body parts emerged, then merged. (How about them Cubs? Dick is suddenly out of pants then in mouth. Nope.)
- Ask her how long they were together, and when in that period of time, the conversation stopped and the action started. (I can pretty much promise you that she will push back on this aspect, claim she doesn't know and so on. Tell her to estimate.)
You will be faced with a hot mess of bullshit answers, but they will be committed to paper, so she cannot claim she didn't say it.
Then you have to decide if this is a person who you can stay with, live with what she did, how she is behaving afterwards, who she truly is, if she is a risk of doing this again, and be able to face yourself every day.
It is always so disturbing when we find out the person we thought was so special is so utterly typical.
Good luck to you.