EXCLUSIVE

The L.A. Kings are responsible for destroying the sex lives of two grandparents ... this according to a new lawsuit obtained by TMZ Sports.

The people behind the allegations are Trina and Dino Adam -- who claim they were at the L.A. Kings Icetown sports center in Riverside, CA back in January for their granddaughter's birthday party.

In the docs, the couple claims they were celebrating in a special room away from the ice rink in the sports center when a hockey puck zipped into the room and struck Trina in the head.

According to the suit, Trina was knocked out cold ... and her husband caught her before she hit the ground ... but she suffered serious injuries from the incident -- including nausea, headaches, mood swings, memory loss and more.

In fact, Trina says less than a week after the incident she lost her balance as a result of the lingering effects of the puck injury and tumbled down a flight of stairs ... fracturing her wrist.

But that's not all -- Dino says he's suffered as well ... claiming in the suit that he's lost the "enjoyment of sexual relations" with his wife.

The couple is suing the Kings organization for medical expenses and other damages.