What a joke "Dad in the building"?
All this happened because of another clip of MC Khovansky, which was released not so long ago. Everyone liked the new song so much, and especially the chorus, that they decided to make it a quote. That is, the phrase "Dad in the building" is an excerpt from the song of the same name "Dad in the building".
If you want to listen to another "miracle" of a musical creation, then Khovansky will sing to you now:
I suspect you have heard about this from social networks in which this phrase is actively forced due to the fact that the video was successful. I can assume that the success of the video caused a violent reaction from fans and the spread of the phrase "dad in the building" as a meme.