Most Helpful Guy
Been there, survived that. (she did it 3 times, thus I'm nearly an expert :-p)
It isn't that easy.
Get tested first. NO unprotected sex WITH ANYONE until you can have an HIV test done, that's about 100 days after unprotected sex. The other STD's can be found after a few weeks.
No unprotected sex with any person until you're tested (AND healed)
#-If you're fed up with him (and IF he has been kind to you), invent another excuse to dump him, like the urgent need to have kids or your family intervening: he'll feel better that way. (I got invited to her marriage and brought a present)
#-If you want to stay with him, don't ever tell it. Yes, you'll have to bear your dirty little secret forever, it will be your normal life. Lots of people (M/F) have dirty little secrets like that.
What isn't known doesn't hurt.
Thus if you tell it to him, it's not for him but for YOUR own comfort.
If you tell it, he might feel justified to do it too, even if you get his pardon. Yes, it will be harder for you than telling it and making him your unwilling 50% accomplice. Live with it and don't do it again. (but you'll probably do it again a few or many times anyway)
Next time, take care not to get an std and/or get pregnant.
USE CONDOMS, damn it!
Btw, if you have religious problems with what you did, convert to Roman Catholicism: you confess to a RC priest , say you regret it , then you say 17 prayers and you're clean like a baby (if the doctors say the same, of course!)
Now, let the down voters come. :D