First?

So last weekend my boyfriend went down on me and I swear that was freaking amazing. He is the first guy to ever go down on me and he said I'm the first he's ever went down on which is kinda a relief. But after that I went down on him and now he doesn't believe that he is the first guy that I've been intimate with... I love him and he makes me so happy but does he really think I would lie about that???