I feel super bad

I was out last week and met up with this guy that I've actually met about a year ago (and I already liked him then). We danced for a good hour and it was really good and... Hm sexy? 🤔😂 Then, at one moment when it felt like he was about to kiss me, he goes "I have a girlfriend". And I'm like shook, wtf?! So I ask him why is he out dancing with other girls like that then, told him it's not fair to his gf, and he goes that it's not the greatest relationship, they're kind of in a bad place now lala, he has a lot of resentments towards her... So again I tell him if he has problems with his gf he should work it out with her (idek why I'm low key giving the guy relationship advice but whatever 🙄) but he goes on about how he really actually likes me and he just wants us to have a good time and dance.

But unfortunately the alcohol got to me and the fact that I liked him and actually was hoping that I'd see him and something would happen... So we did end up making out. He wanted to do more but I didn't want to. And now I feel really bad because I feel super immoral for making out with a guy who has a gf, even though he initiated it...