Trichomoniasis is a sexually transmitted infection (STI) caused by the protozoan parasite Trichomonas vaginalis. The disease can have a negative impact on relationships, both because of the inconvenience and potential health risks it poses. Here are four ways trichomoniasis can affect relationships: 

1. It can cause discomfort and inflammation in the genital area, which can lead to decreased intimacy and sexual pleasure for both partners.
2. It can cause bacterial vaginosis, which is an infection of the vagina that may increase your risk of other STIs.
3. It can lead to infertility in women and decreased fertility in men if left untreated.
4. Untreated trichomoniasis may also increase your risk of HIV or other infections by sexually transmitted diseases (STDs).