Suggestion. My wife and I approached it this way, and it was far better than stories I have heard.
RULE 1: The marriage is the most important thing, sexual playtime is the second important thing.
RULE 2: read rule 1. No surprises. Its a team game. Every decision is made together, not by one.
No one likes to be put on the spot by their spouse. If your husband "surprised" you with a guy and he was not your type, you'd be pissed that he didnt include you in the decision. Same with him.
RULE 3. see rule 1. You cant go back. Theres no time limit. You can tak a step, thendecide together on going another. The biggest pitfall in these things are unintended or unanticipated consequences.
That comes from going too fast. Eat the elephant one bite at a time.
Heres our suggestion:
1. meet your new guy in public, with your hubby, with a NO SEX advance agreement.
It is a platonic, interest generation meeting only. Boundary is that he may touch you under the table.
Hubby may touch you as well. You may steal a kiss. Time limit 30 minutes.
Tell him you will be in touch. You and hubby talk about it for a few days.
2. Meeting 2 is at a hotel lounge. Not your house. Not his house.
You set the boundaries with both men. We used: "same room, Soft play only".
For us, this meant making out is ok. Hands anywhere are ok. Masturbating one another is ok..
No genital to genital contact. Playmates orgasm if one occurs is to happen externally.
On tits, ass, or face, your decision.
HINT At the meeting in the lounge, have a code word with hubby for "I want out of here" or, "I want to go upstairs with you both" We used: "Have you heard from Dana" if she wanted out. Id excuse to "call the babysitter" and come back to get us out soon after. If she mouthed the words to the song "I'm feeling lucky tonight", that meant for me to suggest us all going upstairs. (Its good to have an out if you want one and good that hubby doesnt have to read your mind if you want more.)
Meeting 3 happens after you and hubby both agree that ts hot, you both like it, you both want more.
You can skip the lounge, meet your playmate at the room. You, hubby and he will be ready for full on sex, cuckolding, whatever you and hubby want. And you wont have a guy who cant get it up..he'll have ben with you and hubby before.