Welcome here on hcm.
You have seen two answers here and they give you a way to get rid of this problem.
I am going to teach you how to prevent this type of problem when you have sex.
This complain itself suggest that you always have sex with no precaution of hygiene.
It also suggests that you must be having sex with new partner evrytime, mean you might be sex worker.
While before going to have sex you must clean your body and your private parts thoroughly with a good soap and an antiseptic solution should be used to clean your private parts after soaping.
Ask your partner too to bath thoroughly and clean his private parts with soap as well antiseptic solution after that.
And I think you must not believe your partner in cleaning, as he is not accustomed for it nor serious for that, as he having no such problem as you have, so you should take active participation in his cleaning.
Clean your mouth and ask your partner too for the same if you are going to have oral sex
Never indulge in anal sex in between.
Your partner must take precaution not to touch your anus by the penis while going in to vagina.
Your bed cloths must be changed before sex with a new hygienically cleaned bed sheets and pillow covers.
Clean your private parts thoroughly as before after sexual act is over with no waste of time.
If you want to do sex again after some time with this partner again than again start with same procedure of hygiene as you are going to do fresh sex.
These measures will certainly help you.
Welcome any time.
Enjoy your sex life.