You are absolutelly wrong - Lena is the biggest slut/whore of all! Ivy may also be a slut/whore but she will at best be on second place,the first place it's for Lena who only needed to take Ivy's advice about Stalkfap and trying to have fun instead been in another relationship and then you can see how quickly Lena start to surpass Ivy that also shows Lena how impressed and proud of her she is.
Here are just a few examples: Lena decide to have fun with Robert and on next day even Louise says to her that she is out of control because she just slept with one guy while need to go on a date with another(Ian); Lena shows interest to Mike and then she happens sometimes to preffer call him then Robert while still having Robert on a leash knowing he loves her; after going to Axel's apartment for the photoshoot she decide to let him kiss her and then fuck her; Seeing Jeremy alone in Louise's room she decide to take that oportunity to surprise Jeremy and have fun with him,first sucking him and then asking him to fuck her; at Ivy's birthday party she even blow Mark in the toilets and a bit later she let him shoot her with his camera while he fucks her.... and all of that are only a small portion of all the time Lena's been acting like the biggest slut/whore
Louise: Lena you are out of control
Ivy: You slut,you fucked him
Lena: Ivy was right,i'm definitely a size queen