Parishioners at a Catholic congregation, St Patrick's, Dumbarton, logged onto the church's webcam expecting to watch a live mass, but instead, they were treated to a steamy Durex ad showing couples having hot sex powered by "pleasure enhancing" Durex gel.
The ad ran along with other poorly targeted ads before the live mass came on.
The commercials which, according to Big New Network, came before the church's live webcast of the Mass of the Holy Spirit, showed six women in seven heavens of sexual passion as an opera singer in the background celebrated their orgasmic rapture.
According to The Sun, the advert made it seem that the women in the throes of passion were singing Mozart's Aria, and ended with the slogan,"Sexperience."
One of the parishioners who saw the ad said: "My eyes almost popped out of my head. It's certainly not the type of advert you'd expect on a Catholic church website.You would not imagine it is Durex's target audience but I suppose you can see the funny side of it."
A web user who also saw the ad said: "I was looking for a webcam to check Dumbarton's weather but I landed on the church site and got more than an eyeful. I am sure the flock didn't expect to see naked women writhing about groaning when they logged on for their service."
According to The Sun, the live stream was broadcast by a webcast firm called UStream, which featured the commercials before the cast.
Other commercials that appeared on the live stream, according to The Sun, included an ad for a gambling site and another promoting a service for helping women get pregnant.
The church was unavailable for comments.