Vanderpump Rules star Tom Sandoval is in a legal battle with his ex and reality TV co-star Ariana Madix as she looks to sell their shared home in Los Angeles. Tom claims to have lent Ariana a substantial amount of $90,000, which she has not repaid, leading to a dispute over the sale of the property they once called home, RadarOnline.com has learned. According to legal documents obtained by TMZ, Tom alleges that he provided a loan to Ariana and is now demanding repayment before any sale of the house takes place. He insists that there is a lien on the property directly associated with the allege…