Toothbrush situation

Last night I used my Dads electric toothbrush to masterbate (I know this is already a bad start), but I was super horny and I really needed to. However when I was finished with it I forgot to wash it when I put it back in the bathroom. My dad then proceeded to use his toothbrush this morning.. After it has not been washed. He didn't say anything about the taste or anything but I still feel like I should tell him because it is morally wrong. Any tips? Thanks.