Guy flirts with me and then I find out... he has a girlfriend?

Ok so this is big for me. I had anorexia for like 1.5 years and I barely left the house or went to events. Then I developed Binge eating so I'm like a normal bmi now. I'm coping from day to day. ANYWAY this is exactly what i needed to make me feel good. I went to my friends 21st and started flirting with this guy that I had a massive crush on 2 years back. My friends bf was egging us on & they were talking about rugby tomorrow so I threw into the conversation 'Oh that would be so fun to come and watch ..hahaha...*PAUSE*' so hes like come and watch.

At one point during the night I said 'god theres too many conversations going on at once' then he replied with 'I thought women are suppose to multi-task, are you sure your a woman?' Now...I am very VERY womanly. I have big boobs and hips & look a bit latino so i'm like 'Oh i'm all woman...I mean I can show you if you really want proof' I mean I was totally joking..I realised after I probably went overboard...anyway he went sort of speechless whilst he was pretending to think of a way that I he could prove it.

ANYWAY even before we started talking he was glancing over at me & then came closer to speak to me in the group (like he crossed the group). & SOmehow my friends boyfriend knew i was single. Either he oculd read my body language or she told him...dont know.

So anyway my friend throws into the convo (my friend having the 21st) so do you still have a girlfriend? and hes like 'yeah but shes in adelaide atm...'. NOW i'm good at concealing my feelings but I was really shocked. Shortly after that hes like 'ok i'm going to head off now' and he hugged me and said it was nice seeing me again.

SERIOUSLY! I'm going to this rugby thing tomorrow...I'm sure there are other cute guys that I can see as potentialities...but seriously WTF?