He left the barbecue early because of the flies. He had been afraid of them for years, and his friends had grown accustomed to it. They still invited him to barbecues, garden parties and the like, because it would be rude not to, but they knew he would either decline politely or leave early because of the flies.
He was most likely to attend Victoria’s parties. She had a fly zapper in the conservatory, so he could just about manage to sit in there while everybody else mingled outside. He couldn’t watch them though. If he saw a fly go too close to somebody’s face or hands, he would have a panic attack and leave. If his host wasn’t inside to say goodbye to, he’d just leave a note. She was used to it.
Like all his friends, Victoria had grown used to it as just one of those things, those little things that make people unique. She was scared of balloons, Jack feared horses, Helen screamed at the merest suggestion of a spider, and he had his thing with flies. They had never asked him why.
It was just as well, really. He couldn’t explain it to any of them. He didn’t think of himself as a particularly good liar, so anything he told them would probably raise suspicion.
He certainly couldn’t tell them the truth, that his fear of flies came from his first wife. He couldn’t tell anyone that he had bashed her head in with a spade and left her in the garden shed one summer, until he could dig a grave unnoticed. He couldn’t describe to anyone the horror of returning to the shed to find flies teeming across the unrecognisable remains of her face, drawn by the sticky blood, or how they had flown up around him in a cloud when he moved her.
He couldn’t explain that he was afraid of flies because they would sense the blood that still, even ten years later, invisibly stained his hands. That he was afraid they would swarm around his hands looking for that sticky blood, providing irrevocable proof of his guilt.
And so, with an apologetic, nervous smile, he left the barbecue early, and his friends just nodded to each other and laughed about the harmless flies.