confused as hell :/

So I have been seeing for 7 months and we've talked about being in a relationship a countless number of times but a month ago he was texting another girl to meet up. It didn't happen because she chickened out but I have no idea what to feel because everytime I question him about it he tells me that he loves me and it was an accident. I'm so confused and I have no idea what to do, I really need some advice?