my thumb was black & cracked from years of smoking everyday
his thumb and index finger look like from striking the lighter so many times.
You can also use foil to smoke both, if his snorting it look for rolled up bank noted or pieces of paper that u suspect.... you also need one of these or some kind of pipe to suck up the heroin.,
first, the dry skin between his fingers is probably nothing. if he is smoking crack, look for blisters on his fingers and palms. Also wont be any "cut " lines , as usually ya just break a chunk off and throw it in the pipe. If he is smoking crack, look above the doors and on top of the med cabinets. glass rose pipes and tire gauges are usually the two pipes used to smoke crack. they can be laid on top of the trim of a door and usually not noticed.biggest thing about him smoking dope, is he paranoid or hyped up when he gets outta the bathroom? if he is the opposite, he may be snorting heroin.
either way, if you think he is using an not being honest, confront him!! after all, this is both of your lives he is dealing with!! best of luck to you and urs!
I dont know about herion but crack has a smell, the dry cracked skin is another also goes with it, if his eyes will be dialated, if he is staying in the bathroom that is another sighn, look on the counter for like cut marks or white crumbs, good luck