I'm just learning about tapeworms and other platyhelminthese in my Invertebrate Zoology class on Monday and you should NOT let him lick you on your face if he has tapeworms!!! They are easily passed to humans!! You have to be very careful! Ok I just listened to my lecture again (I record them). If he licks his poo, butt, or other dog's poo that had tapeworms and licks in your mouth (even just you hand and then you rub your mouth) you can get them. They would follow your digestive tract and into your intestine where they'd attach.
They are nasty little devils that can grow very long and are made of a mouth with hooks (scolex), a neck, and segments. A single segment carries everything needed to produce more segements. A tapeworm can also separate it's self at any part after it's neck and create a second worm and attach to another location of your intestine.
A crazy sidenote is there's a tapeworm diet. It's obviously not FDA aproved, so you'd have to fly down to Mexico and buy a tapeworm and ingest it. You follow your everyday routine and it just hangs out in your intestines, taking in nutrients from the food you're eating. You supposedly lose weight and when you want to get rid of it, you just go to your doctor and have it treated. I thought that was insane when my professor was telling us about that. I wonder how many people do this.....
Anyway, I hope you listen to your vet and the others that have posted here. It's nice when pets lick us and show how much they love us but, not when they're battling tapeworms.