Oddly, this situation happened to me two years ago. I was upset, because I very ill, bed-bound, and too weak to even use my wheelchair, and SO at the time would not help me clean it up. His BF came over and cleaned it for me; he even drew me a bath, brushed my teeth, and carried me to and from the bathroom.
That ex is an ex for multiple reasons, but his refusal to help really hurt me since he was very aware of my health issues.
Was his BF single? cos I would have dumped his *** and replaced him with his BF if there was an attraction btw us.