so what do i do?

[rubygem10]

Hi. I could use some good advice. There's a guy I really like. I've known him since we were teens and I always thought he was cute. He is my best friend's nephew and I've known his family for about 20 years. That's how far back we go. He's 3 years younger than me and up until now I didn't think he'd date an older woman lol. He's in the military and is seeing a girl who's also in the military. They've been dating for 2 months. Back in august she reenlisted and knew she'd be leaving her base. She was in a long distance relationship with a fiancée and they broke up in September. Then 2 weeks later she starts dating my friend. She found out where she's going around the same time and its really far. She'll be going to Hawaii. He lives on the east coast. She wants to have a long distance relationship with him when she leaves to her new place. She does have a bad track record with ldr. What she did to her fiancée wasn't her first time. My friend is an amazing guy and I can understand why she wants to hold on to him. But she's going to be gone for 3 years there and he can't leave for at least 2 years.

my dilemma: He recently told me he likes me and has liked me for a long time and never told me. For years we lived very far apart and we didn't keep in touch with each other. We did always know what was going on with each other thru his aunt(my friend). I like him, he's certainly my type, but I don't want to be a side piece. He's really confused as to what to do with his girl. As of right now he's underway and will be for a month, which gives us both time to think. He'll be going on deployment sometime early next year and hell be gone for 9 months. She leaves while he's on deployment so he wont see her off. They wont be seeing each other for a least a year given his deployment and her move wont give her time off so soon. He's really uncomfortable with her leaving to HI since he knows there's good looking guys there she can keep occupied with. He knows her track record and that makes him even more uncomfortable. She's extremely jealous with him. She can't stand me although I've never given her reason to dislike me. Maybe she kind of knows his feelings for me. He's asked me for my opinion and I've told him they don't always work out but some can manage and that he needs to be prepared if it doesn't work out. I tried having one years ago and it didn't work out for me after about 4 months. I was about the age his girl is now when I had it. He doesn't want to hurt the girl's feelings so he agreed with the long distance relationship. I reminded him to be honest with her, especially if he's not going to be faithful. He said he feels like he's putting his privates in a box and handing it to her to hold on to. All the advice I gave him was prior to him telling me his feelings to me, and like a fool I told him I liked him too. He wants me to go down and see him next month and also before he deploys. What do I do? Do I say no like my brain is telling me? or just go with the flow? Any advice is so appreciated. I'm not a smart cookie when it comes to relationships....