Science

My quick skim seems to suggest that this is a correlative study, so the way that this title is phrased is misleading, I think. A major alternative explanation that's completely not mentioned is that people who produce more sperm are also more likely to suspect their partners were not faithful.

For instance, perhaps baseline stress or paranoia induces sperm maturation through some sort of hormonal signaling, and it also causes people to be more suspicious of other people.