Trichomoniasis is not known to acquire from toilet seats.
Since you have not cheated on her anytime, it is difficult to comment on such a sensitive issue.
You may better discuss this with your wife or her Gynecologist.
Both of you get properly treated.
Hope this helps you.
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.