Surprising new wife

A fantasy of mine is to have my wife engage in sex with me blindfolded while having sex getting up to leave and having some one new jump in either with her blowing him and me coming back to slide it back in or the other way around, without her knowing or being aware of what’s happening. I think it’s the surprise aspect of it that interests me or the fact of her pleasing another cock not know the surprise she is in for. Has anyone done this or what are some tips/advice to maybe having this play out. M23 F24