I think we know what qualifies as succumbing to peer pressure (basically following any behavior because peers do it or because of what peers will think of you if you do it). For me, one of my favorite reasons for hanging with Mike is that I never feel (or am) pressured to behave any certain way; I can be me without it affecting our relationship. Because I have him, I've never felt that anyone else is worth hanging out with if they try to pressure me at all, so I've been fortunate. But knowing Mike, I know he is stronger than me and doesn't even need a good reason to ignore peer pressure. To everything on your list, and everything that goes along with those listed, I can (with complete confidence) attest to Mike having never fallen to peer pressure. I usually avoid using absolute words such as never and always, but in this case there is no other suitable word than one that is absolute.