Okay, you are the judge of the situation.. To love and be loved is a blessing... If he cheated on her with you and cheated again.. What does that say about his interpretation of love and lust, are the two mixed up?? Hes warned you telling you that he doesn't believe in love.. You two both want different things... Its up to you to decide whether he genuinely is in love with you or whether he's too materialised...
Sorry, silly comments or questions with not be looked at.
Firstly, when in conversation, DO NOT overthink about the conversation and the things you will ask as well as talk about. Just simply enjoy and go with the flow. This isn't an exam and don't feel pressured you have to say something. Appreciate the moment. And ask the friend to ask permission first. If he says yes to his friend, that is a good start. I wouldn't put all my hope with that initial stage, talk to him first and play off the vibe.
Snapchat him with "Hi" .. reintroduce yourself and start the conversation with last night. On snapchat, you also have the opportunity to personal message people as well, so that would be a great tool. Once you start the conversation, you will build up a little more confidence. Use that to just be upfront. Keep in mind through that it is better to confront your feeling earlier on than having to go through a period of time where the likelihood of getting into the friend zone increases.
This isn't healthy for you at all. This is a time where you need to now get some space and regain that mental strength and see whether you really want to be in this relationship. Once you are mentally strong .. I would suggest to then talk to the person you are in a relationship with. To build that trust says you are willing to let that person grab hold part of yourself. You need to be prepared for that step .. again. If you feel sceptical as to whether to do that .. Do you not just want to be happy and be with someone that appreciate and just care about that happiness and that beauty of yours?
I suggest you meet her in person .. But to answer your question, it will be weird if she doesn't know you. If she does, it will not be weird.
You can't really make someone like you .. and doing it through Instagram is pretty pathetic. I suggest, you send her a personal picture on the private chat, via Instagram, and just try and get to know her. From then on, work with the vibe. So keep pushing forward if she gives dead responses.
It takes time for things to move forwards .. with some people it may be fast or it may be slow. But I suggest you ask him in person what the feelings really are, and see whether they are mutual. If he still carries on with dead responses, it is time to move on.
In all honestly, majority of the attention should be dedicated to you. He should only really just focus on your beauty. It is indeed a guy thing, it is natural but there has to be a limit. If you feel this is bothering you, talk to him. You need to build that trust and he needs to aware of the presence of the trust. Vice Versa.
Of course you are not over-reacting. Truth being told, guys will always have the attractive 'celebrity' .. Its natural. However, having an obsession and a girlfriend, well thats a different matter. You need to find out how he feels towards you .. if he is genuine. Think about whether you actually trust him in the way he sees you compared to other girls. To be honest and in actual fact .. the only beauty he should really be admiring is yours.