Sex Q&A: Allergic to Sperm?
Do you use any lubricants that might get on his penis, perhaps during foreplay? That could be the cause of an allergic reaction. Or it could be something as simple as performance anxiety: We can get panic-type symptoms when we're not sure about what we're doing. However, because of the "numbness" and feeling like your throat is "closing up," this situation concerns me. I suggest you discuss it with your health-care provider. Although it's quite rare for someone to have an allergic reaction to semen, it's not impossible.
Nestpert Dr. Pam Spurr, author of Make Love All Night & Talk to Him in the Morning and Naughty Tricks and Sexy Tips: A Couple's Guide to Uninhibited Sexual Pleasure