One of the common questions we see in this sub is "How do I know if this is just a fantasy or something I want in real life?" For a while now I've been aware there's a crucial difference between a fantasy (an arousing thought) and a desire (something you want to actually experience). For example, many women have rape fantasies. Zero women want to be raped. But not every fantasy/desire example is as clear, and hotwifing is an especially tricky one because the consequences can be severe if it turns out you should have kept it as a fantasy.

I've been reading "Come as You Are" by Emily Nagoski, and I think it's brilliant so far. Key points badly summarized:

Sexual arousal is governed by two systems, Sexual Excitement (SE) and Sexual Inhibition (SI). Basically, gas pedal and brakes. You can give it all the gas you want, but if the brakes are locked you aren't going anywhere. SI is from the part of the brain that handles fear and stress and keeps us from being eaten by lions. Different people have different sensitivities in each. Most people are in the middle for both, but some people have highly sensitive SE and get turned on easily. Some have highly sensitive SI and everything has to be perfect for them to be aroused.

Another key element to arousal is context. Context determines whether being tickled or spanked is erotic or simply annoying. Context can explain why SE and SI are activated in some cases and not in others.

The thing about a fantasy is it's just in your imagination. The context is threat-free. Your brain knows it is giving you a fantasy, and therefore all the things that might stress you out in real life do not bother you. SI is deactivated.

So the answer to "should I try this IRL" is to bring your fantasy out of your head and into a real life context where your SI can activate if it is going to. Ideally you don't go so far that you harm the relationship. Baby steps, baby.

Now, there are other factors besides this that govern whether you should pursue this. I'm not the guy to try to describe all of them. This piece though - I'm pretty sure about. This is why a fantasy is a different thing than a desire.