Peter Kearney, a director of the Scottish Catholic Media Office, made the comments during an appearance on Scotland Tonight.
He had been discussing the latest in the row over same sex marriage after a protest held anti-gay marriage campaigners in Renfrew.
Asked about his comments during a previous appearance on the current affairs programme, Mr Kearney said he stood by his words.
His previous claims were that medical evidence suggests homosexual conduct "is hazardous, is harmful and is dangerous".
On Thursday, Mr Kearney told Rona Dougall: "If you are living a same sex lifestyle you open yourself up to dangers. Having a same sex orientation doesn’t do that but acting on it does. The problem is society says ‘go ahead and act on it’ and there’s no suggestion you shouldn’t and there should be."
Earlier in the discussion, Mr Kearney had been expressing concern about proposed changes to the law which would allow two people of the same sex to get married.
He was particularly worried that teachers would be sacked if they refused to teach gay marriage to children.
Also on the programme was Tom French from the Equality Network.
He said: "Teachers aren’t in schools to share their views, teachers are there to present the curriculum and put forward the range of views of all religious and cultural groups. I think what this shows is for the Catholic Church this isn’t just about protecting their right to uphold marriage in their way but actually they are opposed to same sex relationships."