You can prefer one invitation without ranking the people who made the others.

Choosing between two invitations is a decision about an evening, not a verdict on anyone’s worth. The ranking comes later, usually invented, sometimes by you and sometimes by the person not chosen, and it turns an ordinary scheduling conflict into evidence about the friendship. Preferences move with mood, distance, and how tired you happen to be that week.

Decline in a way that names what you chose rather than what you avoided. A short honest reason beats a vague one that leaves room for interpretation. Then make the next plan with the other person while the goodwill is still fresh.