what does it mean when he puts his hand on my thigh?

what does it mean when my boy friend puts his hand on my thighs? he is my first boy friend and well i had my first kiss with him too and before him i would talk to guys but the most they have done is hold my hand or grab my ass but like what should i do when he puts his hand on my thigh? should i hold his hand or idk kisss him or something else ? like we were just sitting together in the car and he put his hand on my thigh and i didnt know what to do so i just kept eating my food with both of my hands