"There are two gay members in the Cabinet at least," Mr Parris, said on BBC2's Newsnight. "Chris Smith is openly gay and Peter Mandelson is certainly gay."
Mr Smith came out some years ago, but Mr Mandelson has preferred to keep his sexuality private.
Mr Parris said: "I don't know what he [Ron Davies] was doing on Clapham Common. It is true it is a gay pick-up place. That is not necessarily why he was there but if he were there for that reason, I reckon he's the last generation of politician who is going to have to get involved like that.
"You don't come through Welsh Labour politics by being an out gay member of Parliament. He wouldn't have got anywhere. If he were gay - and I don't know that he is - I can understand why he would be reduced to this, and I would feel sympathy for him."