My boyfriend can't ?

I'm 15 and I'm dating a 14 year old boy but I think he is sterile? We were about to have and he was getting naked and he was like..totally hairless except for a few pubes and I asked if he shaved and he said he didn't want to talk about it so I just forgot about it. Ok, he was REALLY small but I didn't mind but after 15 minutes of , bjs, hjs, then 45 minutes of intercorse he didn't sperm at all and I really want to have kids some day. I asked him why and he told me he let it all out masturbating but thats like not even possible right? I saw him masturbate before and he didn't come then either? I asked him how often he shaves his face and he said its natural smooth? Ok what is wrong with him I thought I was dating a man not another girl?