Using lubrication, eg, KY jelly, may help reduce friction and discomfort during intimacy. However most commercial lubricants contain preservatives and other chemicals that may affect and slow down the sperms. Saliva contains enzymes that kill bacteria and digest food. So both are NOT recommended if trying for baby.

Natural lubricants that are safe are raw egg whites (make sure don’t swallow to avoid getting salmonella infection) or vegetable oil, like olive oil. There are ‘fertility safe’ lubricants which are marketed as being safe for conception, eg PreSeed.