Swapping is a lifestyle that once started is difficult to stop. You will need to think about the consequences very seriously. If you think it is a one off thing, it is not. You will keep experimenting.
There are some dangerous pitfalls in this lifestyle. Jealousy is one of them. At some point, if you are all together, you may feel that your wife is paying more attention to her partner than to you. Or you may feel that she is moaning louder with her friend. This may create a rift when you are both having an arguement and one of you may bring up this topic.
There is often a tendency to cheat. Swapping may lead to one of you meeting your swap partner without the knowledge of your own partner.
Sex can be great between you and your wife, if you allow her to fantasize aloud when making love to you. Continue imagining that you are with the woman you are dreaming about. Pretend that your wife is that other woman. This way your fantasy will be fulfilled and you will reap the benefits of great sex.
You first need to have your wife's consent in clear terms. Do not presume that she will aqgree after you have made all the arrangements. Finding suitable swap partners is never easy and takes unbelievable effort and persistence. You will need to decide atwhose place you will swap or will it be at a hotel? Imagine the embarrassment if there is a police raid and the explanation you will have to do!
Whatever you decide, do not do it out of compulsion. And always insist on using a condom.