Okay, this is going to be long but bear with me, hopefully someone out there has had a similar experience:
Last night my ex and I had sex for the first time in just over 3 months. In this time neither of us had done any sexually acts w/anyone else(really, we share a small studio).
At first we decided to use a condom(trojan magnum) to be 100% safe(I am on the pill), but the second he went inside me I got a burning sensation that only intensified the long he was inside me. So we ditched the grabbed the astroglide and went at it. The sensation slowly went away, but right after when he ejaculated into me I got the same feeling but twice as strong, it would intensify when I would urinate afterward and it lasted for a min 20 minutes, slowly dulling. I think I now have an allergy to his sperm, but I was wondering if maybe there was another answers besides STDs, because we are both clean(yes i'm sure).

PLEASE NO SNIDE REMARKS! If you post ANYTHING MEAN I will report you for abuse.
I don't know if it matters but the condom was 3 years old(the last time we used condoms lol) and not spermicide was used