I think he cheated

Ok so last night I had to work from 8pm to about 6am when I left he was still out with his friends. He texted me around 3 and said he will be there to pick me up from my job. He never came not even a text to say he wasn't coming. I live about 10 mins from my job but its the fact I didn't wanna walk by myself. I got home still not there I get a text saying he fell asleep. still He got home around 8 This morning and also this morning I found out that his ex girlfriend is back in town and he has cheated on me before with her in the beginning of our relationship but now's she back and he was gone all night and wouldn't text me back. What do I do