Nah, he said "someone who cheats on her hus.....", he cut himself off.
I can see that as meaning he is at least subconsciously suspicious of Debbi, who is legally still married to another man.
Or, I can see that as meaning he was involved with another married woman whom he might suspect.
Or, the couple knows a cheating wife whom they think is suspicious.
A few different possiblities, imo. One thing for sure, it makes no generic sense in the context it was given, which was what kind of person the couple thinks would snatch their baby. I think that leaked out of Jeremy because he is pondering some specific uncomfortable thoughts. JMO...