Bangkok - A Thai man and his girlfriend are shopping at a furniture store. She sees pillows on sale and gets excited, her feminine voice falls suddenly to a deep male-like tone. Shocked and horrified, her boyfriend runs off.The advertisement by Ikea, the world's biggest furniture retailer, has incensed a Thai transgender group which called it "negative and stereotypical" and "a gross violation of human rights" in an open letter to the Swedish retail giant. The 20-second commercial shown on YouTube and on Bangkok's trains in December and January entitled "Luem Aeb" ("Forget to Keep Hidden"), was disrespectful to transsexuals, according to the Thai Transgender Alliance, which demanded an explanation from IKEA.Transgenders are widely accepted in Thailand and are commonplace in the fashion, beauty and entertainment industries, but are not officially recognised as women.A marketing official at Ikea Thailand, which opened its first store in the country in November 2011, said on Thursday it had talked with the group in response to its January 9 complaint."IKEA has spoken to the group over the telephone and the conversation went very smoothly. We are now drafting a letter in response," the official said, declining to be identified.