That could never have happened in my own married life because our daughter always looked so much like and took so much after my husband - and NO, there were NEVER any other possibiilities - that I used to tease him with, "I KNOW she's YOUR kid, but sometimes I wonder if she's MINE - and I'M the MOTHER!"
OF COURSE I would have been upset if such a thing HAD happened! If a couple hasn't established a workable degree of mutual trustworthiness within the time it takes to create, develop and bear a child, then what DO they have going for them!?!
If a man has realistic reasons to doubt his wife's fidelity and STILL makes the decision to continue living with a woman whom he considers to be THAT untrustworthy, then he should be willing and prepared to just accept her children as his own for raising whether they are biologically his or not.
If he has NO reasonable base for empty suspicions, but plagues her with them, anyway, then SHE would be better off without HIM!
In either case, it would be counter-productive and unnecessarily emotionally enturbulating for both of them!
Paternity tests have their value in divorce settlements, but WHATEVER the outcome, in an ongoing, continuing relationship, they have far too much potential to cause more harm than good.
logic and speculation