Is it normal that i have sex with the same person since high school?

ok I'll start with a back story. Every friday, me (and my friends M and A) used to walk home together on a quiet road and matthew's mum came and picked him up, so then we kept walking then soon after we started making out and ever since then we've been having sex (behind the youth club outside our school most times when it was quiet) and then we went to the same college, and there was a load of quiet spots there were no-one went at lunch.