This female and I are friends with benefits. We've had sex only once and now it's all I can think about doing with her. This past week though she's been texting and flirting with a teammate of mine a bunch. So now I am extremely confused and don't know what to do. My main worry is that the girl and I will lose the emotional and physical attraction we have for each other. How can I keep it going strong?

You have to quit caring about having sex with her bro. Women don't like needy men. The only way to stop being needy is go find another one.

Just hit her up again and tell her to come over for drinks and/or a movie. This is code for come over and bang. I'd hit her up no more than once a week. Its not FWB just yet, its just a single hook up. Once it becomes a regular thing then its FWB. FWB are awesome because it's no strings attached sex. Especially if you really are friends with the girl. My FWB right now really is a good friend of mine and if we stopped hooking up then we would continue to be good friends. That's what I like about it. What sucks is it isn't a long term thing. Once she finds a boyfriend then its pretty much over.

For now, just play it cool, dont act attached or needy and invite her out for another hookup. Assuming the sex was good the first time, and she doesn't have any issues/regrets then she should want to meet up again. Good luck.