Brian Austin Green and model Tina Louise have called it quits less than one month after they were first spotted together in Los Angeles, Us Weekly confirms.“Tina and Brian are taking a step back from their relationship,” a source tells Us. “Being compared to Megan Fox, every man’s fantasy, is very hard.”The BH90210 star, 47, and the Australian model, 38, sparked relationship rumors in June when they were photographed leaving a taco joint after a lunch date.