Shaykh , i do not wear hijab and even shake hands an play with my boy cousins who are 10 to 12 , they havent reached puberty yet

Be careful. Taking extra care is better for them and for you, and it ensures they are raised properly—especially knowing they are almost at the age of puberty, so they understand limitations. For the 10-year-old, though, it's a lot less, insha'Allah, unless you see that he's close to puberty. Barakallahu fiikum.