Threesome advice/help

Hi all need help so for the first time threesome topic came up today with my husband of 8 years . He was joking about it and I said hmm I never new you were interested he said I brought it up so I am .... he also said ok decide who you bringing in. And I told him no it's your choice in a joking way... and we kinda stopped there. Now I kinda have been thinking about it and I'm interested but I don't want to do it with someone we know... i am also a shy person I'm not sure if I will enjoy it? And not so happy about my body either.. what do you guys think should I give it a try? How can we find someone that will be interested in one time with us. Any personal advice will be appreciated.