I'm wondering if this is another one of those "ignore it" times though, or if that's too much of a "head in the sand" approach?
Well, you aren't ignoring it regardless - you are talking about sabatoging his lotion. Heck, I'd be really upset - and you have a right to be pissed about it. If he was telling you the truth about his finger being swollen, he'd not be hiding his finger.