Very true. I suppose if I was in your shoes, I'd probably end up keeping it to myself under the guise of not wanting to burden them until the other party figured out something was wrong and then it would end up being a thing. You should probably learn from my hypothetical self and err on the side of honesty. It's one of those things they are always talking about being important in relationships, after all. And your guilty conscience probably does have a point and will not stop trying to make it, if it's anything like mine.