We took a risk and bought two young (a few months old) pigs to make life a bit better for our bereaved older pig, and well, because we like guinea pigs and we're happy to have more. We knew they might not bond.
Original introductions went well. One of the new pigs is clearly quite timid and he has really taken to the older pig. The other new pig seemed ok but in the last few days has snapped at the older one a couple of times and chased him. He hasn't snapped back, despite being so much bigger!
We've only had them a week and I really don't want to give up on the bonding yet.
Guides I've read online don't tell you what to actually do to improve relationships - me saying "that's enough of that!" clearly not being of any use!