My siblings, wife, and most of our relatives are very boring re our DNA.
However, we have several friends, who got some fairly big DNA surprises re unknown brothers and sisters until they got their Ancestor.com data.
Most of the surprises have worked out as positives.
One of our medical care professionals recently found out that his “Dad” was not his “Dad”.
My wife had an Uncle, who just disappeared right after the Korean war began. He apparently left his first family and went about 200 miles away and had a different surname/family. He got married and left a wife and 3 kids under that name. His oldest daughter did not want any connections with his first family.
We know close to a dozen couples with some type of hidden or kept quiet DNA links. As noted above, most incidents have
ended up as positive.
My sister-in-law found out her brother was a half brother. OOPS, mom had an affair.