Adam Lambert & Boyfriend -- The Scene of the Crime

Here's a photo of Adam Lambert and his reality star boyfriend ... hours before they snapped and attacked each other at a gay bar in Finland this morning.

The couple -- and a female companion -- were hangin' at a local gay bar called Don't Tell Momma ... where they got into an argument that got super-violent.

As we previously reported, both men attacked each other -- and were each arrested for multiple assaults.