Here is a hypothetical situation for you.
Suppose your baby is having trouble sleeping, unless held or otherwise pressed against his mother. Suppose his mother works full time and has a long commute and is very stressed out by this, but is doing her best to accommodate the baby's needs. Suppose your older child has been plagued by sleep troubles his whole life, making the subject of sleep quite fraught with tension, to begin with. Take a moment to imagine that.
So, given that, let's say, on this particular night, the baby's mother has been holding said baby in her arms and nursing off and on for 3 hours. It is 9 PM. Let's say, in an effort to remain sane, she reached for her iPod and accidentally wakes the baby. Let's say that the baby waking is kind of the last straw and makes the mother give up and want to get ready for bed, since she has to be up at 5:30 anyway and will most likely be up nursing several times before then. She is visibly frustrated. So, the mother then gives the baby to YOU and asks you to hold the baby while she gets ready for bed, which will take no more than FIVE MINUTES.
What would you do? Would you,
A. Hold the baby for five minutes.
B. Hold the baby for 2 minutes, think that the baby has gone back to sleep and try, despite your knowledge of the above situation, to put the baby in the crib in and effort to "help" the mother get some free time, thereby waking the baby and possibly the older child (due to screaming baby), and thus unleashing the wrath of the mother upon you.
Take your time before you answer.