Blow up in somebody's face - Idioms by The Free Dictionary
blow up in somebody's face
blow up in (one's) face
To have a plan go wrong or awry. Mike was trying to sabotage my campaign, but the plan blew up in his face when I overhead him talking about it. Tina's decision to invest only in technology stocks has really blown up in her face.
blow up in somebody’s ˈface (of a situation, plan, project, etc.) end or fail suddenly, with bad results: Starting up the business was difficult, and it all nearly blew up in his face when his partner fell sick at the last minute.