How old is the little one?
Bonding isn't very fun, in all honestly. It's stressful, nerve wracking and even when your holding that towel, your breathing has stopped as your hearts now in your throat you have to stay out of it. Easier said than done I know believe me!
The pigs decide how stressful the bonding will be, I stress very easily not a good mix. I have had pigs bonded so easily or not so easily it does really depend on the pig. Introduce on Neutral ground, plenty of food. everything must have two exits so no one can get cornered. A towel at the ready just incase. Do not put your hand in if they do fight as bites are pretty sore.
Have a look at the boar introduction sticky to tell you what all the actions mean and grit your teeth once introductions begin be prepared to stick with it. Alot of people say only separate if blood is drawn I do separate when they properly fight I just can't bare the thought of someone getting hurt rolleyes.
You may find the older boar, fathers the baby. There will also be some humping and alot of noise from the baby.
Clean out there new home and rearrange it so it's fresh when you put them in there cage.
Good Luck xx