"I am, in fact, into that kind of thing!" Being into that sort of thing is a big reason he got into learning about poisons and alchemy, after all. "Never heard of that marijuana stuff though. Is it any good?"

"And sure, might not be a bad idea. Never hurts to have more supplies, right?" Or they're just going to get distracted and get high, but there are worse things he can do with his time than getting blazed with a gorgeous, half-naked woman. In fact, it's pretty high on his list of "fun things to do when not getting into trouble."