Rep. Milo Smith, R-Columbus, chairman of the House elections committee, outlines rules on testimony on a proposed amendment the state's constitution to ban gay marriage during a hearing of the committee at the Statehouse, Wednesday, Jan. 22, 2014, in Indianapolis. (AP Photo/Michael Conroy)

WASHINGTON -- Indiana's House Elections and Apportionment Committee advanced a constitutional ban on marriage equality last week, voting 9-3 along party lines. Now, the gay son of the Republican committee chair who successfully pushed the measure through, state Rep. Milo Smith, is speaking out, saying he's "terribly disappointed" by what his father did.

Chris Smith first posted his thoughts on the Facebook page of the LGBT advocacy group Indiana Equality on Saturday, three days after his father's committee passed the ban.

"I'm not here to badmouth my dad," he wrote. "I'm terribly disappointed in his decision and beliefs, but he's not going to change them now if he hasn't after all these years of knowing I am gay. I am here to support you and my friends who remain in Indiana. They are my extended family."

On Sunday, he wrote another post on his own Facebook page that read, "My stand puts me in clear conflict with my own father, who is a state legislator and has voted to pass the resolution out of his committee and onto the full House for a vote."

In an interview with Nuvo, an alternatively weekly publication in Indianapolis, Chris Smith said he resides in California and is in a domestic partnership. He said overall, he felt "really sad."

"I'm embarrassed. I'm really disgusted by the whole thing. I'm confused as to what I should do," he said, noting his father had not given him a heads up about the legislation or how he would vote.

When asked for comment, Tory Flynn, a spokeswoman for Indiana state House Republicans, said she spoke with Milo Smith after his son's post went up.

"He stated that he loves his son very much and this is a personal issue," she said.

The House Elections and Apportionment Committee was never even supposed to vote on HJR-3, which would amend the state constitution to ban same-sex marriage. The measure was originally set to receive a vote in the House Judiciary Committee, but after backers realized there weren't enough votes for it to pass -- several Republicans had expressed concerns -- House Speaker Brian Bosma (R) moved the measure at the last minute to Smith's committee, which was considered more conservative.

HJR-3 is now in the hands of the full chamber, and a vote could come as soon as Monday. The Indianapolis Star polled the 100 members of the state House on where they stand on the legislation and found the body is now evenly split between supporters and opponents, with a quarter of the chamber still undecided.