Another option ...
Telling and not-telling all at once aren't your only options. You say you've been hinting. Maybe you could take that to another level? For instance, you probably spend time together away from home. You could have an unexpected need for a restroom and have a little "accident" while out. I mean really small, like a small but visible-if-you-look spot on your jeans. Follow-up later with a bigger one if you "happen" to get a UTI soon after that. I mean, not a flood, but noticably wet. Then start wearing "because you need them right now."
Watch his reaction. If he's accepting, then try being "a little bit little" around him while wearing and spending intimate time together. If all that goes well, you can say later that you discovered that really kind of liked it. Maybe he'd be willing to do it again sometime? In this way, you can step up bit by bit, but you also have a way to back the level down if you get signals that it isn't going to be accepted.
I don't mean to be a contrarian, but I don't think your bf has to engage in every part of every one of your sexual fantasies for you to have a meaningful and joyful relationship. If you read a lot of posts like this you'll realize that a lot of abdl's stay toether--even happily--to partners who don't share that part of their life. They either don't know or chose not to recognize it openly. In fact, I think that is more common than a couple who engages fully in this aspect of one partner's sexuality.
Finally, I'd say that if you want your partner to support you in this part of your sexuality, then plan that at least half of your times together won't have any hint of it. After all, if you want him to do what works for you, you need to be open to setting your preferences aside for him. That's actually what love is about--setting aside your wants and needs as a gift to the one you love. And when it's real love, that is a joy, not a loss. Its a delight to give things that cost you something to the one you love.
Anyone who has had children knows this side of love all too well. There are times when almost our whole lives are given away for their benefit. I remember sitting up one entire night slowly injecting tiny amounts of re-hydration fluid into my daughter's mouth with a syringe while she slept. She was desperately ill, dehydrated, and couldn't hold any but the smallest amounts of liquid down without vomiting. By daylight, I'd gotten enough water into her that she started that day to get well. I, on the other hand, felt about as bad as I ever had. I was up for two days without a break to care for a sick child-- a child whom I loved enought to die for. Did I feel put-upon to care for her like that? No way! I was delighted and greatly relieved that she was doing so much better. Love sacrifices joyfully.
I think that attitude is the key to any intimate relationship. If you bring a willingness to sacrifice your desires for your partner, he'll probably reciprocate--especially if you ask him to. And if not, its better to find that out before you are married.