Mark Salling -- State Farm Is 'Despicable'

Mark Salling doesn't buy that State Farm is like a good neighbor .... he's suing the insurance company, claiming its refusal to cover him against sexual battery allegations is "despicable" and "malicious."

TMZ broke the story ... Salling was sued by a woman who claims on one occasion when she was dating the "Glee" star ... she insisted that he wear a condom during sex but he refused and forcibly had unprotected sex. The woman -- a former Playboy model -- claims she went to his house later that month to demand proof that he was STD-free, and he responded by pushing her to the ground.

Salling claims in his lawsuit the State Farm homeowner's policy requires the company to foot his legal and other bills connected with his defense, but State Farm has repeatedly refused.

Although there's no mention as to why State Farm won't cover Salling, we're guessing the insurance company is hanging its hat on a provision that excludes criminal acts from its coverage.