Conservative Senator Roberto Gerlein on Tuesday condemned gay sex, calling it “repulsive.”

Gerlein made his comments in Congress as it debates a proposed bill which would legalize gay marriage.

Sex between men is “dirty, repulsive. It is sex that deserves condemnation and is excremental sex,” Gerlein told colleagues.

The 73-year-old senator's rant lasted nearly 20 minutes, according to the weekly Semana.

“The homosexual has a smaller hypothalamus, it is a condition which comes imprinted in the biology of the homosexual. He has no way to remove it. He can visit all the doctors and will still have no way to take it out. It is unfortunate that nature imposes this burden on someone, because being a homosexual is a burden,” Gerlein said, then added that he's not anti-gay. (Video of Gerlein's rant is embedded on this page. Visit our video library for more videos.)

The bill's author, Senator Armando Benedetti, said he found the comments to be “xenophobic.”

Gerlein, a member of the Conservative Party, is the most senior member of the Colombia Senate, having been first elected in 1974.

If approved, Colombia would become the second Latin American nation behind Argentina to enact marriage equality. However, unlike Argentina's law, Benedetti's proposal does not give married gay couples the right to adopt children.

Further discussions on the bill were postponed until next week.