Neck pain and ejaculation

My boyfriend gets these severe neck pains at the base of his head where it connects to his neck right before and after ejaculation and it normally lasts for quite a few minutes afterwards. Its the worse when he lays down afterwards. The pain is so severe at times that his eyes start to swell up. He is even afraid to move his neck too much afterwards because he is afraid taht it is going to hurt even more. He is a smoker and to his knowledge his family doesnt have any heart diseases. So, im wondering what this could be or how could we figure it out.

[jtb7]

Sounds like a coital headache. Only other explanation for a headache due to sex is  a brain hemorrhage. Which if it was, your boyfriend would probably  be either dead or severely disabled at this point. Coital headaches are harmless,but just go to the doctor and get him checked out for sure.