Christmas gatherings involve family and friends and couples of all ages, so it is a good time to observe how people behave. Do not start this observation with any plans or preconceived notions, and do not make snap judgments. Just watch.
In particular, watch how the wives behave in regard to their husbands. You will have some wives who pay very little attention to their husbands. You will have some who are very attentive. You will have quite a spread of behavior, but watch.
I watched this weekend at a gathering I attended. There was an older couple there (older meaning 20 years past retirement). They have long ago reached the age where many couples seem almost oblivious to each other, or so we would expect.
Yet, throughout the event, they were clearly a married couple. Their love for one another was obvious. They did not hang all over each other (as young couples do when first married), but dealt with one another as adults and as lovers. I was impressed but not surprised, because I have known them all of my life. It is a comfort to have a couple whom you know will always be together, because you cannot even imagine them apart.
Watch the couples among your groups. Watch how they interact, where they sit, whether they ever acknowledge one another.
Too often, you see what I also saw this weekend, a couple who interacted almost entirely in a negative way. They dealt with "problems" and wifely complaints about multiple things, none of which were important in the situation.
You would expect (from a shallow point of view at least) that a young couple would be more loving, not less, and that there would be more warmth and passion in their relationship, but it is not alway so.
Watch. You may be surprised.
Then, ask yourself what someone would think who was watching you.
You may be even more surprised.