This is of no use as a recommendation as it happened probably about 20 years ago but I had something like this in an Edinburgh Sauna, London St I think, or possibly Scorpio. It was a porno type busty blond Geordie, which was unusual at the time as the girls were mainly local. It was not as prolonged as the videos but employed the same licking technique without actually going in the mouth. Due to my youthful impatience I was starting to wonder when the proper BJ was going to start, then she hit a magic spot in the V shaped bit under the glans and I just went off like a volcano. You could probably hear my screams in Fife and I felt like I was having convulsions. It must be something in the Broon Ale, never had anything like it since.