Don't know the whole story behind this (other than "a buddy") or how much other footage there may have been, but having watched several different friends fuck my wife over the years, I can tell you that it's not really uncommon for the friend to not last very long the first time or two (assuming this was their first time). Keep in mind your friend has probably been fantasizing about fucking your wife for most of the time he's known you, so getting to actually do it with your blessing is a big fucking deal. There are nerves, excitement, all of that. Nothing to be ashamed of at all.
I have one particular friend who unloaded in my wife's mouth literally about 30 seconds after she started sucking his dick the first time. And afterwards he even admitted to jerking off before he came over so that exact thing wouldn't happen... but it did. Again, nothing to be ashamed of, and it's actually pretty hot in its own way. And I can tell you for a fact that it's very flattering to the woman to know that she turns a friend on that much that he can't keep from cumming. Anyway, just another point of view from experience.
an dutchbart :I can relate. We're a black couple living in South Africa. The first time my wife got fucked and creampied by another man other than me, it was with my best friend. I told her about my fantasy but she was reluctant to go along with it. This one Saturday afternoon she came back from work and found me chilling with my best friend. She decided to go and refresh in the bathroom and I said to her that my friend will assist her. She just laughed and went into the bathroom. After I confirmed that she was fully settled in the bath, I called my friend to come and wash her back. When he came into the bathroom I asked him to undress and help her clean herself up. He was already spotting a hard on after seeing her naked for the first time. He undressed and climb into the bath and in no time he was deep inside her. We took the party to the bedroom and she got creampied the whole night. Epic experience.