Does a slight pulse or tremor in the vulva, which may occur due to tight clothing, or during sleep, or upon hearing suggestive words, or when studying parts related to the reproductive organs, accompany the discharge of manī (sperm/seminal fluid), knowing that no wetness is observed on the clothes, but normal vaginal discharge may appear?

Mere pleasure does not necessitate ghusl (ritual bath); rather, ghusl is obligatory if you are certain that semen has been discharged. The discharges mentioned might be madhy (pre-seminal fluid), in which case you must wash whatever part of the body it touched, sprinkle water on whatever part of the clothes it touched, and perform wudu (ablution) for prayer. You are not required to investigate if you are in doubt about anything being discharged.