I feel like I'm pretty good at seduction but for some reason I'm so passive when it comes to making that final move on a girl, usually I wait until it's VERY clear to make my move and last night although it was clear to me I was easily deterred. Details below:

I met this girl at a club a few weeks ago, she's new to the city and I've been inviting her out to group outings and what not. Last night her and her housemates had a house warming party and she invited me. As an aside, we made out the night we met and I later asked her out on a 'date' which she declined because she 'wasnt looking for anything right now'.

That's okay with me because I really just wanted to establish a FWB, but anyway.. the housewarming went well and we were together for most of the night. We love talking about music so eventually we went up to her room to listen to some music, now here's where it gets kinda fucked, people were leaving the party and were stopping by the room to say bye to her, so I decided to make my move after everyone had left, but there was this guy who was either intentionally or unintentionally cock blocking me by joining us in the room to listen to music, for the most part I was okay with it because this girl explicitly told me I could crash at her place, so regardless I knew I would be the last man standing.

Eventually he left and almost immediately she said something along the lines of 'we aren't going to have sex tonight but we can cuddle' and I just kind of accepted that... I KNOW that she was using that as a personal defense to not seem easy and I KNOW I could've easily used cuddling as a way to escalate to sex but I just didn't, I just didn't pull the trigger for some reason.

We ended up talking for a bit and then went to sleep together, I woke up this morning and after a while said goodbye and left.

I know the next time I see her I need to be more aggressive but how can I prevent myself from being neutralized so easy, has anyone else experienced this big of a fuckup? I'm kinda pissed at myself.