Let’s start with the positive of this aspect – for gay sex (both male), the tension of especially the square, makes sex mind blowing. It’s almost as if one is edging the other on, figuratively and literally. It can be animalistic as well, although that might be better described by Mars – Pluto synastry.
I suppose also, in competitive sports where one party must win especially by strength, this aspect brings out the fighting spirit and physical strength of the sportsperson, which might lead into injuries (?). However, if it’s critical for the sportsperson to keep a cool head during the game, then this aspect certainly won’t help with that.
Based on a sample of two, which admittedly is not a lot, this aspect creates too much tension and friction which could be described as a clash of will and desires. So when one’s wants are obstructed, that person may fly into a rage and assert him/her self more, prompting more action from the other person. In relationships, one person should be receptive and just “allow” to reduce the tension in the relationship. Presumably, this would be easiest for Mars in mutable signs owning to the adaptability of them. However, I wonder whether the person adopting the receptive role may develop cancer or sickness as the energy is directed inwards unless of course, that energy could be directed into something else.
I imagine it takes self-control to thrive in this relationship. Maybe the motto for a romantic couple with this aspect is “Make love, not war”. For non-romantic relationships, perhaps be crystal clear on the goal and direct all energies toward that common goal. If there’s a conflict on how to approach the goal, perhaps a third person may be helpful.