But that is nothing, I mean, he has already shown me his pants (white boxers from US store Banana Republic) even though we met only 10 minutes ago.
It is fair to say the Glasgow-born singer, actor and presenter is living up to his cheeky reputation.
The examination of my shins came when I asked him what it was like playing a woman in his last theatre role, camp musical La Cage Aux Folles in London last year.
“It was liberating. But I hated shaving my legs,” he confessed.
“Do you shave your legs? Let me feel!” he says, rolling up my leggings.
Fun-loving Barrowman was born in Mount Vernon, but moved with his family to America when he was nine.
Now 43, he has forged a career that started on the stages of London and Broadway and later took him to the Dr Who Tardis as the doctor’s pal Captain Jack, who became so popular he got his own spin-off show, Torchwood.
He has also just filmed a guest spot as murderer Patrick Logan in American TV network show Desperate Housewives, which will soon be shown on Channel 4.
But now he is ready to spend much of the rest of this year back in Glasgow.
In the summer he will film a second series of his Saturday night hit show, Tonight’s The Night, at the BBC studios at Pacific Quay.
And then there’s panto …
He is lined up for the starring role in what is claimed to be the UK’s biggest festive pantomime, Aladdin, at the Clyde Auditorium this Christmas.
It will offer a special twist on the usual “It’s behind you” gags of panto with 3D sections. Producers also promise Barrowman will fly without wires.
He might have built a career out of being rather loud and brash, but Barrowman also has a caring side.
When he was a child at Mount Vernon Primary he used to organise Opportunity Knocks contests in the playground. When he returned there for a visit recently he took the time to track down a pupil he had teased on an earlier trip to make sure the child was not offended.
He also asked the teacher to send him a list of all the children’s names so could send them all a signed picture (whether they want one or not, it seems).
John’s already had talks about a part in all-singing, all-dancing smash hit TV show Glee. He is also reported to be working on a show with his parents. They have been married 56 years and Barrowman says they are the people he most looks up to in his life.
But what about Doctor Who?
Will Captain Jack meet the new Doctor, Matt Smith?
“Haven’t been asked,” he says, “but if I am I’ll go at the drop of a hat.”
But it really does not matter to him what he does -- just as long as he is in it.
“People say, ‘Do you watch yourself on television?’ Yes. I love it because it is something I have dreamed of doing from when I was a little boy.
“Scott (Gill, his partner) says, ‘What are we watching? and I reply: ‘We’re watching Desperate Housewives because I’m on it’. He says, ‘Do we have to?’”
One show Barrowman did not do this year was Andrew Lloyd Webber’s latest talent search Over The Rainbow … because the BBC asked him “too late”.
But would he have auditioned as a kid? He shrieks excitedly: “Who wouldn’t want to be Dorothy! I could have been Nancy! As long as eeeeeeee neeeeeds meeeeee!” he warbles, before crashing back on the sofa in hysterics.
“No. I would have put myself up for those roles. The boys’ roles …” he says breaking into a wicked giggle.
Of course John. And with his manager hovering it is time to finish our chat.
Now, in case you have not guessed I am a bit of a fan -- a ‘Johnette’ as we’re known.
And I have one question on my list I have not asked. But he has grabbed my crumpled piece of paper. He reads: “What is it like being chased by women when we sadly have no chance?”
He squeals. Wrestles me on to the sofa. And makes kissing noises from behind a cushion.
One thing is for sure, with Barrowman back in the city, Glasgow is in for a treat.
Aladdin is on at the Clyde Auditorium from December 11. For tickets call 0844 395 4000 or see the website: www.ticketsoup.com
Video is at www.eveningtimes.co.uk click on video and audio.