Star Trek legend William Shatner is obsessed with riding and breeding horses — but an expert warns equine lovers get sexy kicks out of dominating the powerful animals! The 86-year-old, who played space explorer Capt. James Kirk on TV and in flicks, breeds saddlebreds and quarter horses on his 360-acre Kentucky farm and rides the animals in shows. In his recently released book, Spirit of the Horse: A Celebration in Fact and Fable, Shatner reveals he is “wonderfully, hopelessly in love with the creatures.” Top behavioral expert Dr. Lillian Glass says it’s more than love, noting there’s a sexual thrill linked to mounting and controlling the large, muscular beasts. Buy GLOBE today to understand Captain Kirk's fascination with horses!