Ok I really need advice please?

ok me and my guyfriend want to do something but behind our parents backs (we want to exchange clothes for a little bit and just hang out) but his mom wont let him hang with girls and my mom wont let me hang with guys) but after school we are going to walk across the street to a abandoned like place and exchange clothes their his mom thinks he staying after for band my mom thinks im getting tutored and well im feeling really guilty and i really want to do this but idk what to do really we have been trying to come up with a plan for doing this for 3 months and finally we are actually gonna do it and its this tuesday after school im scared to even walk off of school property and do it just because im scared i will get in trouble i have never got in trouble at school and im actually a good kid i have good grades and im smart but geez i dont want to just not do it i really want to do it so bad but im scared that my mom will find out and i will be in huge trouble and lose her trust idk what to do but I really want to do it but not get caught