Husband advice

I'm in a weird situation. My husband and I got married in June of last year but we've been together 8 years. He's never been the type to go out on weekends. He started a new job the first part of jan'16 and now the last 4/5 weekends has been going out every Friday or Saturday. The first few weekends he wouldn't tell me where he was and shut off his phone after claiming he was only going to Walmart. Then he'd come home at 2am and say he just needed time. Well This last Saturday he claimed to be hanging out with an old friend and spent $100 on drinks for him and his friend. I had a funny feeling so last night I checked his texts and sure enough his friend had canceled on him and my husband still went out and stuck to the story that he was with his friend. I calmly asked him and he said he was for sure with his friend and regardless the text he actually called him. I then asked if I were to look through your phone logs, is there record of this? Where he said no. But is still sticking with he was honest and went with that friend. I don't know what to do here? Anyone have any sound advice?