I need advice - please no rude comments

So I’m 18 years old and I’ve been dating this guy for almost 2 years. Recently, there’s been this guy that has caught my attention.. he always talks to me and smiles at me and while we are talking we just blush the whole time and I just think so much and I get so guilty about it because I love my boyfriend but then I realize I’m still so young and I wanna experience more. This guy seems so genuine and sweet, but I’m so scared that if I do end up with someone else, they’ll never treat me as good as my boyfriend does (honest, faithful, loving). I don’t know what to do. Anyone out there been in my shoes? If so what did you do?