Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concerns.. As per your complain it seems that burning sensation in throat after swallowing semen is either due to inflammation in throat that has occurred due to frictional rubbing of the genital inside mouth or can be due to infection in throat secondary to improper maintenance of genital hygiene.. Sexually transmitted infection does not seems to be a cause as of now because sexually transmitted diseases that commonly occur like Chlamydia, Gonorrhea etc has an incubation period that is a time duration in which there are no symptoms of disease after exposure to infected organisms.. So as you have been exposed just now, chances of STD are less.. I would suggest you to consult an Otolaryngologist and get evaluated and a thorough clinical evaluation and investigations like throat swab culture can help in diagnosis and treatment can be done accordingly.. You can be advised a course of antibiotics, anti inflammatory painkillers and also do warm saline gargles.. As of now you can start gargling with a numbing mouthwash containing Lignocaine to relieve burning and can also take Ibuprofen.. Take a soft bland diet.. In future also it will be better to use proper protective measures like condoms before oral sex to avoid exposure to infections.. Hope this information helps.. Thanks and regards. Dr.Honey Nandwani Arora.