How do you bring something up that is a touchy subject? By hinting, of course. Just make sure that you are subtle about it. If you hint too much, she’ll know that you’re fishing for something, and you’ll look like a fool. Hints are best done when there is a
natural centre for the subject. Let your girl’s response to that give you cues. If she seems interested, then leave the door open for the future. Remark in an off-handed way that maybe someday you two will explore that avenue. If she’s interested, she will likely bring it up again. If she’s the shy type, then you will have to hint a little more. The key is to be persistent, but gentle. And remember that light humor can always break the ice.