Mason did look up, just for a second, as he felt Ainsley getting up. He followed the bloke's movement out to the kitchen, but then turned his attention back to his arm before the vampire turned around to head back. He wanted to trust him, and he supposed that he did, but the years of his mother drilling it into his head that all vampires were bad were hard to ignore.
"Yeah, okay. Thanks," he nodded also, pulling the towel off his arm after Ainsley moved into the other room. He was very careful to fold it in such a way that he hoped no blood was showing. The scent, perhaps, was still there, but maybe if he couldn't see it... Mason didn't know how it worked for the vampire, but he didn't want to tempt him.
Then he carefully maneuvered his shirt off over his arm, piling the bloody and dirty shirt on top of the towel. Only for a second then did he think of how he must look - hair all asunder and covered in dirt and, oh god, the scars all over that usually only his mother saw- but then he focused on pulling some paper towels free and folding them to put on his arm.