Is my son gay?

My son Aiden is 18 and has a best friend Ethan. Him and Ethan have been best friends since 8th grade. Ethan has constantly been over our house since middle school and we see him as family. He even calls me mom. My son and Ethan have always been very close but I've noticed things and it got me thinking to things I may have missed when they were younger. Back when they were 15 or 16 Ethan had a girlfriend and my son would jokingly say "You're still my husband" and Ethan would jokingly kiss my sons hand. They made jokes like that all the time when they were younger. And always slept in the same bed during sleepovers. Ethan still comes over our house. In fact they're always together. They even have showered together before. I have seen Ethan grab my sons hand. They say I love you to each other. I'm stuck because girls do this stuff all the time with their friends, so maybe some guys are just super close, but I just don't see guys doing this type of stuff with friends. I'm sure there are some guy friends out there who are hello close but Idk of that's the case with my son. Opinions?