I don't say things straight into the other person's face. I kind of like to make a joke or a remark and make it digestible or just give a little comment that voices my concern, but is not meant to be a critique, but just a comment so that he understands that I am thinking.
I offer Emily half of my hit of acid- Love Saves the Day. It's my second or third time tripping, Emily's first, and she's understandably trepid. Awake all night, at one point I find her touching her reflection in a cruelly lit dorm bathroom, asking if she'll ever be the same. I kiss her then for the first time and whisper, No.