Nick Gordon -- Begs Bobby Brown ... Let Me Mourn at Bobbi Kristina's Funeral

Nick Gordon desperately wants to attend Bobbi Kristina's funeral Saturday ... so he sent Bobby Brown an email begging him for his blessing.

According to the email, which we've seen, Nick says, "I loved Krissi with all my heart and I am destroyed that she is gone and I need to say goodbye."

Nick realizes he's on the outs with the family as cops continue their homicide investigation with him in their crosshairs.

Nick, who included Pat Houston in his email because she's arranging the funeral, goes on, "I'm begging you both to please put your differences aside and allow me this chance."

And there's a dash of guilt laced in the email ... "Krissi loved me very much and she would want me there."

Nick was persona non grata the entire time Bobbi Kristina was hospitalized, with most members of both families blaming Gordon for BK's death.

The irony shouldn't be lost on Bobby Brown ... he was blamed by Whitney Houston's family for her death and even left her funeral early after a disagreement over seating.