Suleiman Al-Sadi, from Bristol, said members of staff at a store in the city whistled and laughed at him while he was shopping for a sofa last Tuesday.
He said he was "shocked and horrified" when they made jokes about his "camp" appearance.
DFS said an investigation was under way and several staff had been suspended.
Mr Al-Sadi said "five sales guys" looked at him and started laughing when he walked into the shop at Cribbs Causeway.
He said one of them joked they "should probably take him to look around the beds".
"I was shocked, confused, horrified. A couple of them started whistling. I felt like I'd stepped back into the 1970s.
"They were trying to taunt me. It was making fun and jokes of my appearance. They didn't take me seriously."
Mr Al-Sadi complained to DFS. The company said it was "disappointed" to hear of the allegations and was "taking it extremely seriously".
A spokesman said: "We have apologised to the customer for any unintentional distress caused and remain in regular dialogue with him as we look into the issue further.
"Following the complaint, a formal investigation is under way and several employees have been suspended pending completion of the investigation.
"Should anyone be found to have breached our standards, further disciplinary action will be taken."
A number of employees at a DFS furniture store have been suspended over allegations they made fun at the appearance of a customer.