simply being horny about people is not boundary-crossing or sex pest behavior, but also feeling guilty about it doesn't mean you're infantile or sheltered or puritanical or whatever. we live in a culture that is very weird about sex, simultaneously telling people that sexual desire is wrong while also being abysmal about normalizing crossing sexual boundaries, so I deeply sympathize if you struggle with feeling like you're doing something wrong if you fantasize about real people. it is, however, sex pest behavior to ask random people without prompting if you have their "consent" to fantasize about them or use their photos as masturbation material. do not fucking do that.