I really don't know what this means

Hey, so I posted a few days ago about my current situation. To sum it up, I have a girlfriend and we're long distance right now, and I feel like the more time we're about, the more time I realize how we're not that compatible. The other complicating factor is that I've always been attracted to her mostly straight friend (who I've been referring to as S), and S has been joke flirting with me for weeks. I feel like S and I would be way more compatible and she has the personality I've always wanted in a long term partner.

Anyway, here's where the new stuff comes in and the part I'm super confused about.

My girlfriend and S and a bunch of their friends were hanging out the other night, and I was joke/tease/flirting with S a bit. One of my texts was a bit more sexually suggestive than any of the others I'd made before, but in a funny way so as to hopefully not be taking too seriously. (I can let you all know what these said in a comment on this post if you're interested). S doesn't respond for a while, I consider sending another text to apologize but decide against it because I can play it off as a joke anyway.

I'm going to put the text convo with my girlfriend that happened like an hour later because this is where I got really confused.

Me : Are you drinking yet?
GF: Yeah and S is drunk
Me: haha already?
GF: She said she wants to show me her room
Me: What are you drinking, I have a cran-raspberry vodka
GF: Is it ok if I go?
Me: Of course babe
GF: Hahaha oh okay! I'm drinking a beer soon I guess haha
Me: You're drinking a beer soon?
GF: lol I'm not drinking yet
Me: You said you were?
GF: S was texting for me
Me: What? I'm so confused
GF: lol when I said 'is it okay to go to S's room" S said that and was joking.
Me: Oh okay I was wondering why you were asking permission. I was like 'are you planning on making a move?' haha have fun drinking!
GF: Lol that's what she was playing at. ohhhh S haha

So that's what happened and I'm still so confused! Like S obviously wanted to see how I would react if I thought my gf was going to make a move on her, or vise versa. I'm assuming she wanted to see if I would get mad/jealous/upset at my gf for insinuating there might be a hookup between them. But I don't know if it's because she likes me and wanted to see if I'd get jealous or if because she thought the joke/flirting had gone too far and wanted to if I was actually into her (and she wasn't into me). Oh and btw she did eventually reply to the sexually suggestive text with "Lololol that was good" which is something because at least it wasn't too inappropriate that she just completely ignored it.

Please let me know what you think about the situation, I'm happy to share any more details. I'm just so confused about what went on and I don't know what it means.

 

Anyone....? I really need advice.

And for anyone who reads this and thinks I'm a terrible person or whatever because I have a girlfriend, this is not all one sided. My gf has started recently been talking to the girl she cheated on her last girlfriend with. It's not a trust issue, I definitely trust her not the cheat on me because she said she never would, but at the same time she knows this girl only wants to hook up with her when she's not available. So even the fact she wants to hang out with this girl is acknowledging that she wants to spend time with someone who finds her attractive and she has a history with. I'm not upset with my girlfriend, I just don't think long distance is for her, she's too affectionate and is still too upset that we're not physically together, but we're only a few weeks in to what will be at least 2 years apart.

Anyway, the relationship is not perfect on either side. I don't mean to complain, and I'm not looking for advice for what to do. I honestly am only looking for advice/reactions to the above post. If I can feel more certain about whether S does or doesn't like me, I can determine what to do with my current relationship.

PLEASE reply, I would love any bits of advice or how you all interpret the above post.