yup, they're considered same-age friends but it's only inside infinite, because if you're following the standard age cutoffs and all, sungyeol is myungsoo's hyung. but myungsoo is considered an 'age breaker' too. i changed out one of the 'hyung' usages in the links and this is just one of the other reasons why myungyeol are so close - for sungyeol to accept myungsoo as a same-age friend when he doesn't have a concrete reason to