Is it worth it?

Ki

So there’s this guy I’ve been talking to for months and been having sex with, and we have, what I thought was a good bond. I let him vent to me, I finally put my guard down with this guy. He lives right across the street from me, and just now I seen another girl bring him food and they both walked inside his house. I’m so mad inside and feel betrayed. But we haven’t made it official, so do I have a right to be mad?