Let’s work this through.
The polka dot girl looks like she wants to eat me. The girl in red looks, by the way she is sitting, a bit lazy and would give up sucking my cock fairly quickly. The girl in green is probably a lesbian as she is touching the girl in red and being touched also by the girl in blue. The girl in blue wants to fuck the girl in green as she is touching her on the leg. The girl in black is maybe a bit shy as shy people always sit on the end.
But still, I’d go the shy one. She looks like she has the most potential for cutting lose.