It is difficult to surprise Aventurine- after all, the man has gone through all the circles of hell to be here and now as he is
And he's naturally very fond of you. Of course, sometimes the past bites him in the ass and unsure thoughts start to creep into his head, but he doesn't let them settle in his head. He loves you, he's happy with you, that's the main thing.
Even if you don't see each other that often, it doesn't upset him. Or rather, very upsetting, but he doesn't say it out loud, only constantly pulls you into bed to hold him, or hides his face in your stomach while you play with his hair. In fact, anything to be close and feel the warmth, the warmth of another person. Also, to no one's surprise, he likes to spend money on you. He really, really loves spending money on you. And if once, unconsciously, this was just his way of trying to buy your love, or more correctly, to make sure you wouldn't stop loving him, now it's just... grown into his love language.
So his surprise when you bring him something from your errands is unbelievable. It's like somewhere... there's been a mistake.
It's hard to surprise Aventurine, but the emotion with which he digests the information is hard to name otherwise. "Say that again, sweetheart," he says, as if in a puff of breath, taking off his glasses, his eyes fixed on the trinket you brought after errand.