Assalamu alaikum, when I pray my 2 years old son crosses my prayer place and sometimes sits on it or comes to me in tashahhud and sits on me or touches me. does these things invalidate prayer if he has najasah in his diapers?

Ustadh AbdulAziz al-Haqqan

My two-year-old does the same thing as well. No, it does not nullify that; the salah does not affect it in any way.