Why do guys smell you?

Why do guys smell their fingers after they finger you? I never realized that my boyfriend done it until I see him do it the other day. I know that he knows that I wash down there with feminine wash because he was with me when I picked some up. I was just curious as to why they do it? I know I couldn’t possibly smell as I take a shower and wash before I go to his house. I’m not sure how I feel about seeing him do it.. I feel like he smells me just before he eats me out like he’s just seeing if I stink or not before he goes down. Is this a normal thing? Do I actually smell and not know it? It didn’t bother me that he does it I was just wondering 🤔