In a bowl, add the ground beef, mustard, barbecue sauce, Worchestershire sauce, diced onion, egg. Once the Instant Pot screen says HOT, fry the two pieces of bacon until crispy. Turn the Saute button off by hitting ‘cancel’. Remove bacon and cut using either kitchen scissors or slice with a knife. Add the bacon to the mixture and mix with a wooden spoon.
Roll about a huge tablespoon’s worth of meat mixture with your palms into meatballs. (I like to lay the raw meatballs on a baking sheet)
Wash your hands prior to turning on the Saute button again. Brown the meatballs. Transfer to a plate when done browning. Do not overcrowd the meatballs.
Turn off the saute button again. Place the meatballs back in the Instant Pot. Add water. If you need to put the meatballs on a second layer, cut a tin foil into a circle and layer it on top of the meatballs on the bottom. Carefully poke holes with a fork through the tin foil. Place the remaining meatballs on top.
Place the Instant Pot lid on; a musical sound will play. Set the manual pressure timer to 8 minutes. It will take roughly 10 minutes for the Instant Pot to pressure.
Once the timer finishes counting down the 8 minutes of pressure cooking time, wait 5 minutes before releasing the pressure carefully.