Hrgh-! Get that away from me...! [He'll try to lean back away from the mug as it's shoved in his face! Aside from that surprise and disgust, it's mostly a glare that's fixed on his face as he looks towards Junko.]

Be that as it may, that drink may just be part of your karmic retribution. [He doesn't quite like dealing with Junko, but at least he feels confident that he won't end up becoming a part of the Ultimate Despair in this world too. He's ready to reject her at any turn!

But as he glares at her, he does start to pin down part of what seems off. Now he tries to look at Junko as little as possible, but he's pretty sure that she didn't have freckles on her face before. Now he starts to look more confused as well.]

...Have you contracted some manner of pox recently? [That seems like the most rational explanation!]