Welcome to Healthcaremagic,
Probably your Intense sexual activity may be the cause for both Swollen perineum
, anal and abdominal pain
Because you both had both vaginal and anal sex.
It is advisable to use the lubrication while having vigorous sexual activity to avoid injuries to vagina, perineum and anus.
It may also be due to Herpes infection or fungal infection
If you have any vaginal discharge
, Fever, Shivering or malodour in vaginal discharge, please consult a gynaecologist.
Hope this helps.