This is an excellent question.
You are right about the questions. Very normal. At some point it may be helpful for your WS to write down the answers too. It may help for reinforcement, help you remember what was said so that you can build on that. Not to stop you from asking questions but allowing you to ask other ones for clarity. It's kind of like when I am overwhelmed I make a list so I don't have to carry the mental load of what's on that list.
As for how it's different.
So, when you are single, your options are pretty much wide open. Yes, there are limitations, we can't all date Brad Pitt. But, ideally your are emotionally open, you have selected someone based on their traits that appeal to you. You also aren't getting the base of your needs met by someone else.
When you are married, you are getting a lot of your needs met. Even if the relationship isn't great but might be "fair" relationships the base needs are often there. In an affair, your options are not limitless. There are far less people interested in starting up a relationship with a married person. So what happens is often there is an opportunity, the person is convenient to them in some way.
If you look at who most people pick to have an affair with, often it's a headscratcher to others. Often the person is really many steps down from the spouse. And even if not, what I am saying still applies.
So, the WS mind is pretty damned avoidant. They do not take responsibility for their own happiness. Instead, they tend to look at something that is missing in their relationship and exaggerate it in their mind. Instead of addressing the situation with their spouse they often think they don't have control over it. They start telling themselves that you are just not compatible in that way. Over time, I think it drowns out appreciation in a relationship and the BS gets taken for granted. As a result things worsen.
Now note that I am not blaming the relationship or the BS. This is the WS's mindset making what is often a smaller problem into these exaggerated things. The WS not managing their own happiness, boundaries, communication with their spouse, etc. But, the result when taking anyone for granted can be the relationship will often worsen or break down further.
Affairs tend to be escapism. Because most people know deeply that having an affair is wrong, cognitive dissonance over what they are doing comes in. So, to combat that, the WS has a lot of justifications and mental gymnastics to do in order to do what they want. Often, I think they are subconsciously looking to feel that need they exaggerated in their head (more sex, more emotional connection, more this or that)
Also, affairs are covert. VERY risky. As a result, participating in them create highs. I don't know if it's adrenaline, or just plan old endorphins. When this kicks in then the need to justify gets bigger, and some of the excuses the WS is giving themselves are ridiculous but not examined. At this point, they are basically a crack head looking for their next high.
Now, back to the fact the AP is usually an opportunity/convenience based person. Generally, not always the WS doesn't even know them well. It makes it so much easier for them to project the things they want to see on this person. Putting lipstick on a pig essentially.
The entire time I was having my affair, I think the AP was really just an audience for my own self adulation. I used him to feel special, to feel better about myself. I wasn't really aware of it because most people, like you said, really only have the high experience when you meet someone and have a new relationship with them. I didn't analyze any of what was happening until hindsight. Noone would really believe I had an affair with the AP I don't think. What happens in most circumstances is the AP is not an appropriate choice for one reason or another.
This isn't every affair, but it describes mine. I have been on this site for almost 4 years and I will say it describes probably 90-95% of the ones that I read about.
So, you have basically a WS who is living in a distorted fantasy world living off their highs like teenagers. But they are not having a meaningful or budding relationship. They are using each other for whatever need they have now exaggerated.
You add in both people are emotionally unavailable, that probably at least one of them is just trying to "win" against the OBS to prove to themselves they are just the bees knees, it's too sick and twisted to be like a regular dating situation.
The WS in turn needs to learn this about themselves and understand the ways they failed themselves, their spouse, their relationship. Ironically, a lot of the ways they have often failed is their own communication, their own self awareness, their integrity, etc. It's an epic fail that can not even be compared to whatever arbitrary things they are holding against the BS.
[This message edited by hikingout at 8:35 AM, March 19th (Friday)]