STD Talk With Boyfriend

So my boyfriend and I have been off and on so many times! During one of the times that we weren't seeing one another, he lost his virgnity to a girl who he only knew for two months! Anyways, things between those two didn't work out and they had a bad falling out! So him and I are back together and everything was going extremely well until tonight when I mentioned that I would like it if he got tested for STDs even though it only happened once and they used a condom! He got really upset with me and accused me of insulting him and questioning his judgement!! He said that the girl he was previously with got tested before doing anything with him because he asked her to! I don't trust her at all because I personally don't know her or her previous partners! I just want to know everyone's opinions! Was I being unreasonable? I just want to be safe and practice safe sex because it affects my health just as much as it affects his! (I didn't know where to fit this in, but him and I are both 18 and I'm still a virgin!)