Its infected. You need to take him to pediatrician Monday when they open

The wet part just looks like granulation tissue that should dry out, just keep it as dry as possible (fold diaper to under umbilical cord so it's not covering that area, don't get the area wet with bathing). The redness could be a sign of an infection, but also sometimes the dried/falling off bit of the cord can get caught on things and pull causing the redness. Try to make sure it's not getting pulled when you change outfits, place in the car seat, etc. Also make sure baby is only sleeping on the back. It's hard but try not to touch it and let it dry out on its own.Definitely call your doctor or seek medical help if your baby gets a fever, there is any streaky redness onto the abdomen, pus is visibly oozing out or there is a change in his behavior (overly sleepy, not taking feeds, etc).Doesn't look like anything major right now, but definitely keep an eye on it. Redness should subside if it's just from manipulation or pulling if you do the above things. Good luck! :)

He has whats called an outty belly button it not uncommon for babies with those to get slight infection take ur baby to dr.tomm

In the meantime keep it clean with salt water. Our little one had a stinky belly button and came away early leaving a weird bit of skin behind for weeks that looked like a little creature moving inside her belly button 🥴 it was really freaky but thankfully keeping it clean and dry and being patient she has a normal looking belly button now 🙈 it’s awful waiting for it to heal though and feels like forever I know! Deffo get it seen to to better on the safe side x