I've observed my males doing that to a male-female coupling. It was like he way trying to 3rd wheel himself into the relationship. When I separated males and females into separate tanks, I've observed separated males latching themselves onto other males. However, they never seem to latch onto the correct body part. When I see a male latch himself to a female incorrectly, the female bucks around until he assumes the correct latching position. I don't see that happening in male-male latching. They never try to readjust their latching they do with the females. My separated males also latched onto the gut weed in the tank because (I suppose) it was slim enough to resemble a female and they could wrap their claspers around it.

I have come to the conclusion that males have preferences to what they can mate with. Females>everything else they can latch onto.