"Who's in the House" was a novelty song and hit single by Fr. Brian and the Fun Lovin' Cardinals. It reached number three in the Irish Singles Chart, and spent 12 weeks in the top 40 in 2000.
The song came from Brendan O'Connor's satirical character "Fr. Brian" on Don't Feed the Gondolas (a comedy game show shown on RTÉ in the late 90s). A rap style song, it parodies the Catholic Church's attempts to be "cool" and "down with the kids" and contains the immortal chorus: "Who's in the House? Jesus in the House".
References
Who's in the House Wikipedia(Text) CC BY-SA