Lying boyfriend

So tonight I dropped my boyfriend off at a friends house so they could drink and have guys night. I didn’t want him driving so I dropped him off and took his car home. Well I checked snap location and it says he was across town. I confronted him and he’s still sticking with his story that he was at his buddy’s house and never left. I know for a fact he’s lying and I’ve told him I know. He doesn’t know how I know. What is the problem? Any advice to get him to come clean? It worries me because now I really don’t think I can trust him.