Thank you so much for your question. It is my privilege to be able to help you.
Trichomonas is a sexually transmitted infection. Although there may be scattered reports of people getting trichomonas through other types of contact, that is very unusual and it is not realistic to assume that you got it any other way.
It is possible that you got trichomonas a long time ago, and it wasn't detected until now. So you may have gotten it from your current partner, or you may have gotten it from a previous partner. However, at this point that is irrelevant. Since you have been with him. you must assume that he is infected as well. You should not resume intercourse until both of you are treated. Whether he had it before and gave it to you, or whether you had it before and gave it to him, at this point is not as important. Now you both have it, and need to be treated.
You should abstain from sex even with a condom. Although a condom does afford some protection, it is not perfect, and you guys are just going to "play catch" with this disease until you are both adequately treated.
I hope you find this helpful. If you have any more questions please feel free to ask me. If you are satisfied, please remember to ACCEPT the answer so that I get credit for my work. BONUSES and positive feedback are always appreciated. Good Luck! Dr. SaulJE