Old flame and best friend

This guy (Trevor) and I had a thing with for over a month and is now a thing with my friend(Taylor). Him and I are just friends but Him and I still like each other but we don't talk as much as we did before, taylor is not his type but I guess their a thing now, I've been nothing but supportive and helpful to them both in this whole situation, and last night I talked to Trevor while we where all at a football game and I guess it was taken as flirting and Taylor's friend Kayla texted me of Trevor's phone telling me to chill, which made things very awkward, Trevor and I didn't talk the rest of the night although he was sitting next to me, I was just being a friend. Do I have a right to be a little upset about this? What should I do?