The singer, who recently released his fifth album Lupercalia, had intended to go without underwear on stage - in keeping with Scottish tradition - but couldn't due to the angle of the stage.
"I was gonna do the whole hog, but I realised the angle you were going to get," he told the crowd at his lunchtime set.
"You see how high I am onstage, people would just be looking at a penis rather than a microphone," he explained to NME after the show.
When asked what clan's tartan he was wearing, he replied: "I don't know what it is but a lot of the bagpipe people here are wearing exactly the same one - maybe it's a T in the Park tartan, I'm not sure. It was from the place where I buy all the furniture for my house."
Revealing his reasons for running into the audience during the set, he added: "I recognised a lot of my Scottish 'Wolf Pack' in the crowd, so I just wanted to jump into the crowd and make love."
> Patrick Wolf 'not doing things to be popular'
Patrick Wolf's full T in the Park setlist was as follows:
'Time Of My Life'
Watch the video for Patrick Wolf's 'The City' below: