It is makrooh to wear tight clothing generally for male and females. You can pray in tight clothing however it is best not to, and the clothing should be in between being too tight and too loose so in between that.- IslamQA
To wear such tight fitting trousers, which reveal the shape of the private area in salah, is Makruh and against the etiquette of salah.
Allah subḥānahu wa ta'āla (glorified and exalted be He) in the Holy Qur’an says,
“O Children of Adam! Take your adornment during every prayer.” (Surah Al-Aaraf v.31)
To conclude wearing tight clothing is makrooh and wearing transparent clothing is not allowed as you will be able to see the skin underneath the clothing. In salah time it would be better to wear loose clothing or wear something like a thoub/jubbah or a shalwar kamise