Definitely tell him about it. Don't explore on the "down low"/behind his back, and I wouldn't necessarily say to stay curious about it. You should definitely explore your possibilities if you're curious. So definitely talk to him about it, but be aware that if you ask him to let you explore, you might not necessarily be able to expect him to wait around, or any of that. He might go explore on his own as well. If this is the case, you might want to suggest the possibility of a 3some.