Love can be a bonfire between these two.
They're both physical, energetic, and passionate. Sexually, everything should be fine - it's the emotional side of the relationship they can't handle. Each has a forceful personality and wants to control the other.
In the end, Scorpio's jealousy may prove the undoing. Aries's many outside interests make Scorpio feel insecure and that brings out Scorpio's tyrannical streak.
Aries won't take orders and Scorpio will never take a back seat. This is an unstable partnership with a low ignition point.