I've been with my boyfriend for 3 years and we stopped using condoms about 8 months ago. He had sex once without a condom 7 years ago. Is there any real reason to worry about clamydia, or any other sexual disease? Neither of us have had sex without a condom on any other occasion and we have no symptoms or anything like that. I was just wondering if it could stay dormant as long as 7 years?

Unless he has been tested, he could have it. Not everyone shows clear symptoms. Both of you, to be safe, should have an STD screen.

Yes, many STD's can lay dormant for that long...clamydia, HPV (warts), herpes. It would be best for you both to be tested. Better safe than sorry, right? ;)