Perhaps you should view your heart - romantic love - as a cookie.
You each have your own cookie, and can do as you wish with it. You can keep your cookie warm inside the oven that is your chest, you can give it away, or you can break it up into pieces to give to multiple people.
If you keep your cookie safe and warm, you'll keep it whole. But where's the happiness if you don't share?
If you give your cookie away, you could have it thrust right back to you, a bit soggy, a bit crumbled, or a bit cracked, but that cookie could end up in the warm oven of another person to be treasured. What if that person doesn't love you anymore? They can toss your cookie, broken into pieces, back to you. It will take time, but you can re-bake it; even then, it won't be the same. The person who threw your cookie back will occasionally see a crumb here and there and be reminded of you, but you are left with scars.
If you break up your cookie between so many people, is it really sharing at all? You are bound to have to re-bake it. You are bound to not be able to love fully. You are bound to lose plenty of crumbs, and you are bound to be broken like that cookie you decided to split up.
Oh, but the joy truly comes when you've shared your cookie and you receive a new one to keep warm. Having another person's cookie warm and precious in your oven gives you meaning, gives you belonging, gives you hope. Don't forsake it. Don't break that cookie.
Maybe the moral here is this: treat love as a fragile cookie, easily broken and meant to be kept warm. If it is broken, then it leaves scars on the beholder, and crumbs with the counterpart.
Crumbs to crumbs, cookie to cookie. That's the way we crumble.
