Casual sex?

So I’m at uni and I recently split up with my boyfriend around a month ago. I’m all about having fun and trying to live a more freeing life now. There’s this guy on my course who I’ve been like “talking to” and we’ve met up a lot to work and hang out. I went to a party at his the other night and we ended up making out and sleeping together.. he wants to continue doing this but he wants to ‘keep it casual’ so that there’s less pressure on the both of us. What is this?? Like is this an ok thing to do?? I feel kind of weird about it but I like this guy and I did enjoy myself.. is he just using me?