should I take him back?

Br
My boyfriend and I have been dating for a year and one month. We broke up once or twice for less than a week each time just because of arguing, but we always fixed stuff and got back together. We broke up again in October and kept talking for about 3 weeks and got back together the beginning of November. Things were going good until about 3 weeks ago. We broke up again and we were almost to the point of us being okay again when I find out he had sex with a girl back in October and he might have had sex with his ex the past weekend. Both times he had sex with these girls we were broken up but still talking. He hid the first one from me until I confronted him about it and he finally gave in and said it was true but he was being stupid. The girl is said to have The Clap (an STD) and I'm worried he has it now. He swears up and down that he doesn't have it and I told him the only way we are going to fix things is if he gets tested for STD's. He resides and says he's fine and he knows he doesn't have it. But he says he loves me and wants to fix things. What do I do? I love him and I want to fix things too. He made a mistake and everyone does. I just need some opinions from other people because I'm so confused on what is the right thing to do. Thanks!