Military marriage?? Sort of??

I have a little bit of an issue. I've been talking to this guy in the military for about two months now. Nothing is official. We're actually more like really really close friends who flirt but tell everything to each other? If that even makes sense. He's a pretty comical guy and very outgoing. Well long story short he just found out that he has to get married within the next three months in order to keep his income. So basically he asked me to marry him but told me that "it wouldn't be a real marriage because it's more for legal purposes." We talk everyday. I'm just afraid that I'm really going to fall for this guy & I'm going to get hurt thinking this could be a real thing. But on the other hand I'm like would he have even asked me if he didn't like me? This may sound silly but it's all becoming real and I'm not sure what to do. I know military personnel tend to marry quicker than average, but I think this may be different. Any advice would be great.