My girlfriend wants to try all these things with me [cuckold] [denial]

We’ve been dating since we were 15 and we’re both 21 in college now. We lost our virginity to each other and she’s the only girl I’ve ever been with. (We went on a break and she fucked a few guys) but that’s a different story. Last night she was drunk and sexting me I was asking her about any fantasy’s she had and what she said shocked me. She said she thought it would be really hot if we had a 3some and I was like hell ya… But she wanted it to be with another guy. She said specifically it would be hot if she “Rode another cock while I ate her out” Which I was like oh uhh okay. She followed this up by saying it would be hot to be getting fucked in doggystyle while her and I made out. All of this was shocking to me coming from someone I thought was always somewhat innocent and never into that kinda stuff. I asked her to describe what kinda guy she’d want to have and her answer was 6”4 muscular and like 10” cock. All of this is still shocking to me trying to fully understand what she’s wanting sexually.