Washington (CNN) A gay businessman who hosted an event for Sen. Ted Cruz -- a vocal opponent of same-sex marriage -- is apologizing to the gay community for what he called a "terrible mistake."

Ian Reisner, who is facing boycott threats along with his business partner Mati Weiderpass, said in a Facebook post Sunday that he hadn't fully understood the Republican presidential contender's views on gay rights issues.

"I am shaken to my bones by the e-mails, texts, postings and phone calls of the past few days. I made a terrible mistake," Reisner wrote in the post.

News of Cruz's appearance at Reisner and Weiderpass's Manhattan apartment was first reported by The New York Times , which said Cruz told the group that marriage decisions should be left to states and that if he had a gay daughter, he'd "love them just as much."

Publicly, though, Cruz has been a fierce opponent of same-sex marriage rights. He also supported an Indiana "religious freedom" law that businesses, sports organizations and pro-gay rights groups said was discriminatory.

"I was ignorant, naive and much too quick in accepting a request to co-host a dinner with Cruz at my home without taking the time to completely understand all of his positions on gay rights," Reisner wrote.

"I've spent the past 24 hours reviewing videos of Cruz' statements on gay marriage and I am shocked and angry," he wrote. "I sincerely apologize for hurting the gay community and so many of our friends, family, allies, customers and employees. I will try my best to make up for my poor [judgment]. Again, I am deeply sorry."