I feel like a cheater.

I, (19F) have a boyfriend and we’re doing long distance. I have a close guy friend at university and last night at a party he was really flirtatious and a little touchy, (he was also drunk). I was acting like I normally do, but he kind of cornered me and I fear it looked bad. Since it was loud, I was talking into his ear and I think it looked flirtatious. He was also non stop texting me afterwards and I responded to some messages. (Keep in mind, we’re close friends). But, I’m also aware he has a crush on me. I cant say I wasn’t expecting it, but he’s been extremely well mannered and friendly for our friendship, (besides last weekend). I feel bad for not walking away or shutting it down, but again there wasn’t anything he was inherently doing that was inherently bad or “shut down-able”. I told my friends and my boyfriend about it and they both think I shouldn’t worry and that I acted appropriately, however I feel so guilty. I have so much shame I’m restless. I just need reassurance. What do I say to myself to ease this guilt?