In that moment - and just for a moment - Max almost wished Siobhan didn't know him so well, and wasn't so kind. If she'd waited until he could say it, he might never have mustered the courage, they might have been able to put it off inevitably. It wouldn't have been what was best, or kindest, for either of them. He took a step back, just enough not to be touching her, too disgusted with himself to even hold her hand. "I don't want to be." He'd never wanted to be, had tried not to be, would have given anything for those thoughts to disappear.
Intellectually, he knew it wasn't something he could control. It was some cruel quirk of biology, not something he had or would ever choose for himself. His shoulders slumped, his chest feeling like it was falling in on itself while everything else tensed and knotted. "I haven't been -" It was hard to say the words, even to reassure her. "You know I haven't been off - with anyone." Max might not think very highly of himself right now, but he was at least better than that.