i need help with her body language?!

i was kissing my gf and things were getting pretty hot and so i kissed her chest some, i could tell she loved that. then i kinda touched her "area" but through shorts and tights, this is the first thing like this with this girl. she tensed up all over and squeezed my chest and body very Intimately. and she kinda crossed her legs at her feet but spread a little bit more open where i was touching. What does this mean???