We're told Vivid Entertainment approached the 52-year-old Mexican citizen in an attempt to negotiate a deal for a sex tape, but it's complicated by language barrier, expectations of money and basic anatomy challenges.

We got this video of Cabrera documenting his life, showing the proportions of his penis and even its weight. For the record it's TWO POUNDS.

It's an amazing story ... Cabrera says he carries a heavy burden ... his penis has cost him relationships, jobs and it's too large for him to kneel in church and pray.