I’m in a 4 years long relationship with a sweet man who is 4 years younger than me (I’m 28 and he’s 24) but recently, we’ve made new friends, particularly this one guy. I get along famously with him and my boyfriend is ok with it as he’s used to me having male friends (if he wasn’t I don’t think the relationship would have lasted this long) but a few days ago, I started realizing that I care a little too much over my new friend
This new friend is 3 years older than me and, if I’m to be honest, lately the age difference with my boyfriend began bothering me and I’ve been turning more flirtatious with this friend and the more this happens, the more I think about him.
I care for my boyfriend, I always thought we’d spend the several years together (I’m a cynical person so for me to think that most relationships endure through a lifetime it’s difficult, to me it seems like a 1 in a 1000 kind of thing) but this friend causing my resolve to weaver.
The worst part is that I’m afraid of letting my boyfriend go since he’s very unstable emotionally: He’s been a very lonely person all his life and I’m his first girlfriend, he’s absolutely devoted to me, as I was I till now, so I’m afraid of the consequences of me breaking the relationship.
Part of me is scared of what may happen to him if my feelings for this friend grow stronger, but the other just wants to take the leap and I don’t know what to do.
LemonVibe 
[I think you have to think about your relationships in a qualitative and valuable way. I understand that your current boyfriend may or may not be getting kinda boring, and this is okay, it happens alot in relationships. But think about this new guy, and is he just exciting your boredom? Or is he really worth a potential mate. I belive you should value your current relationship alot, as it’s lasted for 4 years. That’s quite a feat. A new guy who’s only been in your life for I’d say tops a year, is it really worth to be considering him over 4 years of time. A girlfriend I once had told me that time is the greatest test for telling whether or not two people are right for each other. I think you should consider these two people, what both of them are really doing for you, and what you’re doing for them. Based on this, you should make a plan based upon your priorities, the act upon it.
[I agree with Raven on the evaluation of your options. “New and Shiny!” can be attractive in ways that “4 year relationship” can’t. Think about why you’re with your current BF. Know that you are NOT obligated to stay with him just because you worry about him.
[Don’t be unhappy just because you think ending it would mess your bf up. Ultimately, he’s responsible for himself.
Women do mature earlier than men, so the age difference at 24 is definitely a factor. I know many women in their 20’s who would not consider dating someone younger than them.