According to TMZ, Alberto Del Rio was involved in a fan incident following Saturday's SmackDown house show in Anaheim.

During the show, Del Rio did the typical heel tactic of ripping up a fan sign, which was a pro-Sheamus sign held by an eight-year-old boy. The mother accused Del Rio of bullying her son, mocking him when he began crying and ignoring her tweets seeking an apology. She in her letter to WWE, "Take signs from adults NOT KIDS! My son was bullied by your Superstars and it is not okay."

The mother reached out to Sheamus after the incident and Sheamus offered to send her son a signed photo and meet up with him the next time WWE is in the area. The story does not note if WWE responded to the letter or not.

Here is the TMZ.com article:

A mother will do anything to protect her kid -- just ask former "Shark Tank" winner Shelly Ehler ... who's picking a fight with a 6'5", 239-pound WWE star after he made her 8-year-old cry.

Ehler -- who scored a $75k investment on "Tank" for her ShoNo towels -- has a serious beef with Alberto Del Rio ... who snatched her son's handmade sign during a WWE event in Anaheim, CA this weekend ... and RIPPED IT UP (or at least tried to).

In the video (above) Del Rio isn't quite strong enough to rip the sign in half (it is cardboard) ... so he takes off small, pathetic, chunks instead.

FYI -- it's standard practice for the wrestlers to interact with audience members "in character." In this case, the sign was pro-Sheamus ... the wrestling arch-nemesis of Del Rio.

But TMZ spoke to Shelly, who says her 8-year-old was terrified by the wrestler's actions and instantly burst into tears. She adds, "Del Rio is a bully. I looked at him and said 'he's crying' ... and he mocked him."