A lot of my college/high school friends got married in their mid/late-20s, had children, and then got divorced. Some have remarried, others haven't. So I don't think it's very unusual for someone in their 50s/60s to have had more than one important relationship like that.

I would find it surprising if a therapist lived without closeness or emotional intimacy, although they might get those things from friends or other family members, it wouldn't have to be a partner who lived in the same home.