Laura Prepon and Ben Foster have called it quits. The pair — who first met as teenagers — officially separated on September 9 and they have reportedly been living apart for some time, according to sources familiar with the situation. TheThat ’70s Show actress is reportedly living in Tennessee, while her soon-to-be ex-husband is still in Los Angeles. Per legal documents, Foster was the one who filed for divorce, claiming they split after suffering “irreconcilable differences.” He also requested the court uphold the terms of their 2018 prenuptial agreement. The exes, who were friends for years b…