This is embarrassing but I need help…

So I met this guy my age from college and we started hanging out as friends, long story short, one day we ended up making out in my car and we tried to have a blow to each other but I couldn’t get hardcore I didn’t understand why but we just thought that maybe it was because it was uncomfortable making out in the car, then we tried to have sex in my house and same story, I couldn’t get hard and this time I thought it was because maybe I was anxious that it would happen again and I’m so embarrassed with him and told him to give me some time. (I wanna make clear that our friendship is NSA, we talked about it) so one week later I met with an old sexfriend and with him it went well, I could get hard as a rock. It’s been over a month and he wants us to try again but I’m really scared that it will happen again. But I don’t understand why it’s happening: I do feel attracted by him (he’s rlly hot lol), I don’t have ED problems (I get my morning wood every day and get random erections during the day) and as I mention I don’t have erection problems either when it happens with other people. Has this happened to any of you? Do you know what can I do about it? I don’t really wanna take viagra or any pill for it cause I don’t have erectile disfunction.