Higgs nodded when Siobhan said she'd let him know once she'd confirmed with Max. The first dinner had really mostly been to irritate Max, but Higgs had found that he'd genuinely enjoyed himself. Mostly because of Siobhan, really, but when Max hadn't been a stroppy child staring into his food, Higgs found that the man could be quite pleasant, even funny at times. Higgs enjoyed making new friends, so he hoped that despite his reservations towards Max, Higgs could at least make friends with Siobhan.
The question came more as a surprise than Higgs had expected, mostly because he hadn't considered that Siobhan might ask why he was busy on Thursdays. It was a fair question, Higgs supposed. He just wasn't sure how to answer it. In the end, Higgs decided to go for the truth, because it would do him good to learn to actually tell people things that mattered. "I go to a support group on Thursdays," Higgs told Siobhan slightly quiet than the rest of their conversations had been. "For soldiers," he explained. She'd seen the medication Higgs had been on, which he didn't necessarily assume her to remember since Siobhan undoubtedly read plenty of people's medical histories day in and day out, but if she did, it probably wouldn't be a struggle to put two and two together and figure out why Higgs went a support group's meetings.