Well... I'm a guy, I've known lots of guys, I know how guys think... and while it might be true... its more likely it isn't. And it really sucks when you find out it wasn't.
Yes young guys can and do throw away years of friendship for a few rolls in the sack, they always have, they always will. Out of 10 that say they really do care....2 might actually be honest while 8 are lying through their teeth to varying degrees. I'm warning you that you need to watch for that because you are who ends up paying for it in the end. Physically and emotionally.