Hi
thanks for your query
Trauma to the lips, is quite common. The soft flesh of the lips and their exposed location make them particularly vulnerable to
injury. As you described you got injured by your boyfriends teeth and cause a puncture wound that penetrates the skin.which later became infected and pus formation
You should not peel off crust over cut .Although this allows the pus inside to drain out, it also exposes the injury and makes it prone to further infection
Avoid applying any dairy products such as butter, milk, or margarine on your lips as this will only aggravate your pain and will make the wound more susceptible to infection. Since this wound is external, you can use medicated creams on your lips as well. However, use these creams only after consulting with a doctor. you may require some antibiotic coverage to fight infection after doctor consultation