Someone who is very forward sexually and is probably the more dominant in a relationship. Can be male or female. Will probably be a very confident person and has experience.
Guy 1: So how did your evening with Julie go?
Guy 2: Man, she's a total lion!
Somebody who likes to 'take things slow' in a relationship. Usually the less dominant partner, and mostly will not initiate anything. Usually looks for a lion in his or her partner.
Girl 1: Hey, you know you fancy Jake like, SOOO much?? Why don't you ask him out??
Girl 2: OMG! No way, you KNOW I'm a total sheep! You're a lion
, I'm not like you.