I think the best narrative to use to correct your situation is of loyalty and friendship.
You are a person that will not betray past promises made to others for promise of a better future.
Even if the childish promise of loyalty was given to your dogs, and even if the promise for a better future is of your entire rest of your life married to someone. anyone. I would love to have a wife that loyal. Your boyfriend just happened to be on the wrong end of your the promises you already made, so he needs to learn to accept you with those promises and then he might even get from you the ultimate promise, the promise of marriage.
Or am I completely wrong about your character?