I'll keep it short and sweet. Last summer as an intern started dating this girl who was also an intern at the same company. When school came around we didn't really talk has much because we were busy but still texted and I ended up seeing her a few times during the year. We both figured we'd pick up where we left when the summer came back around. Anyway, I graduated, started working for this company full time. She came back and we were good this summer. But one day a few weeks ago she stopped responding to my texts all together and haven't heard from her since. Found out she met another intern and started seeing him. Kind of sucks, and I feel really disrespected that she couldn't have just told me. The issue is I still have to see her work and we are working together on a few things. What's the best way of going about this. Still have feelings for her but I'm more pissed off then sad. Anyone had to deal with working with someone you used to date?

This is why workplace romances are to be avoided. No happy ending here. You will have to be the mature one and treat her like just another coworker.