DS1 had a strong bond with his grandma (my mother) right from birth, and though he had a strong bond with me too he always settled easily for her, was very happy to go to her for cuddles if I had to get something done and I was comfortable leaving him with her for an hour or two while I popped out to the shop or took a walk etc from when he was about 6 weeks old. He was quite a spirited bub but who was holding him didn't bother him at all.
DS2 is totally different, he just wants me 100% of the time. If I pass him to DH or his grandparents he cries 95% of the time and will stop the second I take him back. If I can manage my day so he's pretty much on or beside me 100% of the time he's a super happy bub, if anyone else even reaches out to take him he almost always bursts into tears. He'll be 12 weeks in a couple of days and I can't imagine leaving him for a couple of hours for several months at least.
Was one of your children more attached to you or your DH than another?