Very similar to my best friend with my wife. But the first time was about 20 seconds top. He was so ashamed but she pretended that she loved it and made him feel comfortable. She actually did like it as he is mega girthy so I knew she wanted him again. Besides, I only lasted about 5 min after him as it was just so surreal like you said.
I hear couples say it's hard to find some one to join them. I have had guys just tell me I could have their wife if I wanted her. this was people I knew, and after a few drinks and light smoke.