Lamas' passion for partying was evident almost immediately after she got engaged to Grant, as her appearance on the cover of Girls Gone Wild's June 3 issue was made public the day after he the popped the question during The Bachelor: London Calling's pre-taped finale in May.
While Grant initially characterized the provocative photo spread as a "storm in a teacup," it apparently struck a nerve with the British The Bachelor star.
"After he moved to L.A. and saw her constantly partying and clubbing, he realized that she wasn't behaving like a woman who was ready to be in a serious relationship," a source close to Grant told Us.
"Shayne seemed more interested in getting publicity and being part of the Hollywood scene than she was in the relationship."
However Lamas subsequently denied she cheated on Grant and instead claimed that although the couple hadn't announced it yet, their relationship was already over before her trip to Sin City.
"We remain very close friends," she told Us. "Nothing bad happened between us. We talk every day."
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