Black's request that he stay caught Alastor's curiosity again and he nodded, crossing to resume his seat in the chair he was using as his reading chair. He snorted in amusement at the young man's description of the observant Gryffindor. "I'd hope so," he retorted, casting a smirk Marlene's way, "or she'd be absolutely useless to the division.
While he was still curious as to the nature of this conversation, which was rapidly growing more obscure instead of less so as Black explained who knew and who didn't, what Alastor was more intrigued by was the young wizard's reactions to Potter. Alastor knew Lupin and Potter to be good friends and found it interesting there was such a difference of opinion -- even more interesting that Lupin didn't jump to his friend's defence as Alastor expected.
When Marlene finally explained, Alastor was taken aback. He hadn't known the older Lupin, but he'd since met his wife and had gotten the impression from her she hoped for a reconcilliation. Granted, that had been several months ago now and this did explain some of the odd dynamics he'd picked up on during meetings in the way people chose their positions.
"Pay her no mind. She forgets more people prefer 'the monogamy thing' than don't," he told both young men, shaking his head as Marlene hugged each of them. "She also forgets her healer ordered her to rest. Sit, McKinnon, and let them be the gentlemen and come to you for affection if that's what you want. You two might as well sit also, be a good example for her."
Now that they'd brought this to his attention, Alastor was thinking, sorting information into his mental filing system as he did with any other piece of intelligence. "All right, I'll assume if so few people know, there's a reason for it. Care to inform me of that reason so we're all on the same page and it can be taken into account as needed?"
Alastor Moody was not going to congratulate two people for being involved. If they were getting married, having children, that was one thing. Acting on natural instincts was another. But, he would do what he could to see that relationship and the Order could coexist safely.