Pool Time: "Oh noooooo he's a hot dude!!!"?

There was the really cute guy that I met at the pool, and he wouldn't stop starring at me. When I was getting ready to dive into the pool he stopped me and said "nice bathing suit, love the two-piece idea." I blushed and walked away. When I went to tan he came up behind me and said "you might wanna check your bathing suit hun, I think it might be loose." I smiled and ignored what he said, cause I was in love with his blue eyes. When I went to stand up the top of my bathing-suit was sliding down, luckly nothing bad showed. He laughed really loud and said "today is just my lucky day." He helped tie the back of my bathing suit, and he gave me his number. I went home and texted him that day, and he didn't answer. It's been 4 months now. I've seen him at the pool last week and he totally ignored me he was walking with a new girl. Yesterday I found out he went to our school and he was just a grade ahead of me and that's when I finally realized that his girlfriend was my bestest friend in 1st-5th grade. Today he was on IM and he said "hey" and I was really excited so I asked him if his gf was named (i'll call her jen) Jen. He said "yeah she's hot." and suddenly I felt jealus. Tomorrow me and him are planning to go to the pool again, he say's wear the bathing-suit I worn last time cause he liked lime-green. What should I?????? Am I tripping for the wrong guy????