Constantine Maroulis -- Dodges Domestic Violence Bullet

"American Idol" alum Constantine Maroulis just got a big win in court because the domestic assault charges he was facing have been dropped ... but there's a catch.

A judge dismissed the case after Maroulis and his baby mama, Angel Reed, agreed they wouldn't get violent with one another.

The judge said if their relationship -- whatever it is -- is violence-free for the next 6 months, Constantine is in the clear.

Reed had claimed Maroulis kicked her in the groin and pulled her hair during the August fight at their NJ home. Maroulis claimed he had acted in self-defense and got a restraining order against her.

The couple has a 4-year-old daughter.