Lets look at the evidence:
In the episode where the fight broke out in the vic, kat cleaned up her lovers injured hand. We saw his other hand (the left) touching her face. We could also see his wrist, which leads me to believe he was wearing short sleeves.
As far as i could tell, the skin tone was quite dark, but not dark enough to be Ray.
We also got a glimpse of the back of the mans shoulder, and he appeared to be wearing black.
The suspects:
Michael moon - dark skin tone but he wears a wedding ring. There was no ring on the hand that touched kats face. Michael was wearing a black blazer with a grey long sleeved shirt. I cant see him rolling up his blazer sleeve, he would have just taken it off.
Max - he was wearing a short sleeved black shirt. And he hurt his hand during the fight. But he has ginger skin, pale.
Jack - dark skinned, a known womaniser.. but he was in a green t-shirt
Derek - again, he was wearing a blazer & shirt
Fatboy - dark skinned, but was wearing yellow.. plus he wouldnt be able to fund the shag pad
Phil - he was in a black shirt but again, he has ginger skin
Masood - dark skin tone, was wearing a black t-shirt, no wedding ring.. he's been put on a sex ban until he's married, & nobody would suspect the respectable muslim man.. my money was on him, but he was ruled out in last nites episode.
Im well & truly baffled!!!