Affectionate touch is forbidden by the Torah. Chazal added on to this and prohibited all forms of touch. To prevent a couple from touching even by mistake, there is an additional prohibition: a husband and wife may not pass objects directly from one to the other. Ashkenazim, and some Sephardim also prohibit throwing an object from one to the other.
In a time of necessity one spouse may take an object off of or out of something that the other spouse is holding. Similarly, in a time of necessity one spouse may place an object on or in something that the other spouse is holding. For example, one may be lenient at times regarding taking something out of a shopping bag that the other spouse is holding. This leniency also extends to taking something which is not in the other spouse’s hand, but is still on them. For example, taking a bag off the lap of the other spouse.
In a situation where there is a need, a husband and wife may carry something together. For example, if one needs help carrying a stroller up a flight of stairs, and there is nobody else who is available to help, the couple may carry the stroller together.
One may pass a child from one spouse to the other as long as the child reaches out to the other parent. A child that is not reaching out, even if the child is old enough to do so, may not be passed.
If necessary, one may feed a child that is in the hands of the other spouse.
 רמב”ם איס”ב כא, א, שו”ע אה”ע סי’ כ סעי’ א
 שו”ע סי’ קצה סעי’ ב
 רמ”א סעי’ ב
 ארחות טהרה פי”א סעי’ יב, דהוי נגיעה ע”י דבר אחר
 ארחות טהרה פי”א סעי’ לא, לב
 כן שמעתי ממו”ר שליט”א