Thanks for the query to ATD for an opinion,
If after the oral sex your foreskin has been swollen and you are unable to retract the prepuce then it is likely that there has been an injury by her teeth while given oral sex to you and this has caused the inflammation and swelling.
It is suggested that you may apply cold fomentation with ice thrice a day for 15 minutes each to decrease the swelling and it is likely that it shall reduce in next 24 hrs. there may have been a local cut or abrasion which is very likely. Don't try to pull the prepuce back till the swelling subsides as it would worsen the injury.
This is no indicative of any STD so rest assured, the manifestation is purely mechanical and due to local injury by teeth during oral sex. If the swelling doesn't subside in next 24 hrs or increase in size then you may visit your ER.
I hope i have answered your query in detail,
Wishing you good health,
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.