An important reminder: if your husband does *not* go on this business trip, IT IS NOT A SACRIFICE. A sacrifice is something you DO for your spouse that causes you to lose love units for them.
The distinction is important, because there are two sorts of resentment: active and passive.
ACTIVE RESENTMENT is resenting someone for something he/she has done. There is nothing they can do to take back their action; they cannot make up for it. This tends to be simmering and long-lasting resentment because it's impossible for the offending party to take it back.
PASSIVE RESENTMENT is resenting someone for something he/she is NOT DOING. Note it's a very "present tense" kind of resentment. At any time, this kind of resentment can be overcome by the offending parting DOING SOMETHING to stop the resentment.
In the situation you're in, you're faced with choosing to consent to your husband going, which creates ACTIVE RESENTMENT in
you, or not consenting to your husband going, which creates PASSIVE RESENTMENT in
him. The Policy of Joint Agreement, at its heart, always avoids active resentment in favor of passive resentment; once the two of you can agree on a course of action, the passive resentment disappears.
I ignore the possibility of him going without your consent, which is INDEPENDENT BEHAVIOR, a huge Love Buster, and post-affair would be enough for me to evaluate
if I ought to call it quits.