Is praying Salah without wudhu kufr.
In the name of Allah, the most Beneficent, the most Merciful.
Being ritually clean and in the state of wudhu is one of the necessary conditions of Salah, without which the Salah would not be accepted. Saaiduna Abu Hurairah Radiallahu Anhu narrates that the Prophet of Allah Sallallahu alahi Wasalam confirmed this when he said, “Allah does not accept the prayers of the one who is in a state of ritual impurity until they perform wudu.” (Sahih Bukhari p.25 v.1)
With regards to your question, if you do break your wudhu in Salah then to save you from embarrassment hold your nose as if there is a nosebleed and then leave. The on lookers would think that it is just a nosebleed.
The Prophet of Allah Sallallahu Alahi Wasalam said: “If one of you makes something (passes wind) in Salah, he should hold his nose (as though it is bleeding) and leave (the Salah)” (Sunan Abi Dawud & Sunan Ibn Majah)
As for praying Salah without wudhu with the intention to mock or believing that it is allowed, then he is considered a disbeliever. Similarly, if he prays without wudhu due to negligence or laziness, then according to the Hanafi Fiqh there is a danger that such an action can lead to person becoming a disbeliever, as it is a form of mocking as well. (Aapke Masaail p.456 v.2)
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham