Hi... Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concerns... As per your complain dryness in mouth, hairy tongue and altered taste in mouth can be inter-related but it does not seems like to be due to allergic reaction caused by kissing as hairy tongue does not develop overnight and can occur gradually by formation of deposits and bacterial and fungal overgrowth on tongue.. Dry mouth can occur due to a number of reasons like Salivary Gland disorders, allergic reaction to certain medication, long standing dehydration, Oral infections like Thrush etc. Weird taste in mouth can occur due to dryness in mouth as sufficient saliva is needed for proper functioning of taste buds and in the absence of saliva the taste can alter.. You should consult an Oral Physician and get evaluated and ruling out the exact cause of dryness can help in resolving the problem.. As of now you can chew sugar free chewing gum, drink plenty of water and suck lemon drops to stimulate saliva flow.. For hairy tongue you can use a tongue scraper to clean your tongue.. Gargle with 1:1 solution of hydrogen peroxide and water. You can clean your tongue with a soft toothbrush by dipping it in the solution of hydrogen peroxide and water.... Take more of hard chewable foods that can cly tongue with Frictional action. Drink plenty of water.. As the other conditions will improve taste will improve eventually.. Hope this information helps.. Thanks and regards. Dr.Honey Nandwani Arora.