Crush

So each year my school brings back 4 past graduates from that year to work and well I’m texting of them and we are getting pretty close and like I’m starting to like him and stuff and I kinda think he likes me back but I’m not sure if it’s illegal bc now he works for the school but he just graduated like I just don’t want him or i into trouble he was dating someone when he started working so would it be okay if like maybe we dated not sure tho if it’s legal ?