I met someone special and assumed I was the only person he was dating. He has a harem of sorts. It’s been painful to acknowledge my incorrect perceptions (my dating history is 50-plus years old). Since I found out seven years ago, I have gone in and out of this relationship, always thinking it will be different. Is a mature relationship one in which both people are OK with their significant other enjoying dinner or a concert with someone else? Recently, after we were physically intimate he showered, then dressed up nice to go to the opera with another woman. I feel ashamed and stupid. Please help.

You may be dating a narcissist. If so, that’s why he flits from sex with you to playing arm candy for another woman without concern for anyone’s feelings. He enjoys himself and resists real intimacy. Or he believes he is entitled to the attention. He may describe himself as just accepting what women offer him. If that’s his justification, there is truth to it, right?

It must be painful to realize you have been expecting him to be better to you than you have been to yourself. You want him to dismiss the other women and commit to you. He won’t. He is showing you who he is. When will you believe him?

Most of us have asked a partner to change in ways that would nourish the relationship. But how long should we wait? If married, the answer is complicated. When a couple vows to stitch their lives together (for richer or poorer, in sickness or health …) they must continue co-creating that tapestry, unless addiction, abuse or adultery make it impossible. On the other hand, dating is a period of discernment. Individuals may want to bind their lives to a partner, but should never allow that desire to anchor them to an unhealthy relationship. Signs of ill health include relationships driven by adrenaline, or those in which frustration, hurt or anger rule more than 20 percent of the time.

Let’s talk about dating and life stages. Stories like yours are common among teenagers and 20-somethings. That makes sense, right? Teens and young adults are indoctrinated by fairy tales to believe that infatuation is love. They also lack practice in asking directly for what they want and need from the people they date. So young people fail to establish ground rules. But people who are 65-plus rarely do, either. Older adults, many of whom are widowed, fail to articulate boundaries because they don’t think they need to. After all, when they were dating in the 1940s and ’50s, the rules of romance fit accepted social standards. Today, couples craft their own rules. So, yes, a couple in a committed relationship can decide to socialize separately, and with the gender they are attracted to. Alternately, a committed couple can forsake all others, or only socialize when there is no possibility of attraction.

One last thing, the 21st-century dating pool contains more women than men aged 65-plus. Situations like yours happen regularly in retirement communities. Hopefully, knowing that you are not alone will ease your heart. You must also protect yourself. If you want a relationship that is intimate on all levels, don’t settle for less. If you can be satisfied with the occasional hookup while sharing a man with other women, accept that about yourself. But don’t accept crumbs if you know you’re ready for true love.