A waterpik is a great tool for flushing out debris from in between your teeth. Unfortunately, it does not do as good a job as traditional floss because the floss actually wipes the plaque away from in between your teeth. If your boyfriend isn’t flossing as all (like most people) then water flossing is better than nothing. A waterpik is also great for people with dexterity issues who may never be able to floss otherwise. So, yes a waterpik is great, but not a substitute for mechanical flossing.
Good luck and happy flossing!
Until then keep the areas clean and happy flossing!
It is possible that your teeth have shifted. And sometimes when you bite your cheek it's easy to bite it again and again. An evaluation of your bite by a dentist will help determine what's going on!