Mating it fighting?

Was hanging out the washing when I noticed these two spiders squaring up to each other! Not sure if it was a fight to the death or a mating ritual. The one on the left retreated occasionally then slid straight down again and at one stage fell back and was still for a while! Fascinating even though I am not fond of spiders!

Going to a retirement barn dance tonight which should be fun after not having been out for rather a long time!