So yeah. A 26 year old guy is making comments like, "If I was with you my eyes would never leave you." To my girlfriend in DM. She's being receptive, saying things like, you're so sweet and aww.
I find this pervy and disgusting but I assume she thinks it's harmless. What can I say to her? If I just say it makes me uncomfortable she'll say I don't trust her to make her own decisions and get upset with me.
I'm 25 and have to agree with you that it is dishisting a 26 year old man is interested 15 year old girl. I'm by no means implying that 15 is childish, but there is far too big gap between 15 and 26. Thinking back, if I was 15 and a 26 year old guy was messaging me I would be so flattered that an older guy was interested, but I definitely share your view on this situation. I'm not sure what to suggest really, but I highly doubt that she would leave you for him, as tempting as the fantasy of an older guy might be.
If she'd get upset when you brought it up to try to talk with her about it, then she's not taking your feelings on it into account, is she? And that's not fair to you.
If my girl did that (and she's had older creeps trying to get at her before), I'd feel the same way you do, and I'd definitely bring it up and make her listen.
it is harmless. Guys like flattering, girls like being flattered. it's not like they're planning to meet up. as for age? she's old enough, developed enough, sexual enough, for YOU to like her, right? If you don't see her as a child, why should anyone else?