Well, this is going to be long, so be warned.

A year ago, I met a girl. I was on a break with my then girlfriend, so nothing happened, we just went out a couple of times, and there was tension (I really liked her), but that's it.

After my thing with my ex didn't work out, I started asking her out, but she declined, saying that we would be friends. Oh well, that's it. A couple of months later, I got into another relationship that worked and was pretty good...until two weeks ago (more or less).

Since I'm past the sadness and all that, I started to talk to this girl again (we actually never lost contact but our "dates" were so far and between, seeing that she didn't want to disturb my girlfriend). We went to have a couple of drinks, and of course, we started talking about sex and all that stuff. A couple of days later, she said that I could to her apartment to watch movies, get drunk and/or high.

My problem is:

How the fuck do I make my move? I mean, I don't feel love or anything like that for her. I know she doesn't want a relationship, and of course me neither. She mentioned the idea that she's okey with casual sex, and...well, who am I to complain, right?. But I don't know how to make that first move, my previous "sexual conquers" (what a fucking stupid term but I can't think another) were completely different, and they all came from a relationship and all that.

TL;DR C'mon, read it, man. I need some advice, any advice