The idea is that if you are going to enjoy something in front of other people, you bring enough to share. At a group gathering, spouses who confine their PDAs to the kind of hugs and kisses that anyone there might also receive from them are far less likely to make someone who does not have a spouse feel marginalized. There are more people like that than we sometimes suppose.
In my opinion, while you may offer a hug or kiss to each relative or friend as they join or leave the event, this is different than the affection between spouses (engaged couple) during the event.
Our relationship with our spouse is not expected to be the same as our relationship with everyone at the event. So, it is acceptable that the relationship will be expressed differently - without fear or concern that we are “leaving someone out”.
To withhold hand holding with a spouse, resting a hand on the spouse’s leg, wrapping an arm around the spouse, saying “I love you”… because “someone may feel left out” is not justification for withholding these expressions of love.
All it takes is for a couple to have a falling out, and going to a gathering where everyone else seems happy can be very difficult.
Keep in mind: “who has the issue” is important to see. The couple dealing with “a falling out” are the ones with the “issue”. The couple in a healthy relationship do not have the “issue” and do not have a need to “protect” the other couple from seeing their love.
In fact, couples expressing their emotions with hand holding, “I love you”, might be a way that the other couple begins to let go of their “falling out” and focus back on each other. Maybe one of them will reach out to the other and hold their hand, realizing what strong love they have that is just having a “bump” today. Maybe, they’ll make that re-embrace with each other during the event or maybe there will be an “I’m sorry for being fussy earlier today” on the drive home.
So, I say "God bless, Blue Eyed Lady, and those like her family who do not keep back their hand holding, arm wrapping, “I love you”. They are a witness of God’s love between God, husband, and wife. (I know Blue Eyed Lady, you are atheist, but my thoughts come from the thoughts of being a Chrisitian. I hope I do not offend you, just express my words as I feel them.)
People who are single but not by choice and even those who have chosen a life of celibacy can find their lives made more difficult by those who exhibit what they cannot have. IMHO, the rule of “am I enjoying something in front of others that they can’t have?” is simply an extension of the Golden Rule. It isn’t that hard, either.
Again, the “issue” of not having a spouse (by choice or not), is not a justification for couples to “need” to refrain from healthy expressions of love - hand holding, kiss, “I love you,” hand on knee or around shoulder or waist.
If there is someone who has an “issue” with seeing something they do not have (a spouse or a spouse present at the event or a good relationship with their spouse), it is their “issue”. They may want to discover what their underlying issue is with not being able to see healthy expressions of love between spouses.
You may choose not to express affection with hand holding, a kiss, etc. in front of others because they “might be hurt” because of their own relationship or lack of relationship. Their “hurt” does not come from seeing the love of others, but from something deeper that they might want to address and heal.
Others don’t hold to the idea that love should not be expressed in such cases.
None of us are ever equal on any issue. One man has a missing leg, another has two missing legs, one person has a spouse who is deployed to a war torn nation, one couple has faced years of infertility, another has 5 children and grandchildren, one struggles to meet monthly bills, another is homeless, another has plenty of money to share…
We are all different. For those who are blessed to have a loving spouse, who are blessed to be in a good relationship today, if they desire to kiss, hug, say “I love you” - they do not need to be restricted because someone else may have problems seeing their expression of spousal love.