Do you think 11 is too young to?

My brother is 11 and he has a "girlfriend", it's pretty harmless as they just hang out and jump on the trampoline and go to the beach and stuff (so far). However, he is being bombarded with "advice" from the older boys in his scout troop and friends about what 'they do with their girlfriends, etc." and I'm worried because of some comments he's made, such as "____ is so hot! She's my girlfriend now". He refers to random girls in public as "hot" "y" etc. which is kinda creeping me out, since he's in 6th grade. I guess he's just growing up but his friend (whose also 11), has a "girlfriend" who gets naked with him. I mean I'm his big sister and I should protect him, I did not date until I was 14 (2 years ago) and I am still a virgin and planning to stay that way, I do not consider myself a prude but this is icky stuff they're doing. Any words of advice to handle this? What should, if anything he be doing? My parents are ignoring it.