Cold sore or Canker Sore from Kissing?

Okay, so I admit. I've been making out with my boyfriend for these past couple of days. Except, here's the thing. Every time I kiss him, I get what I think is a canker sore. Though, it may be a cold sore, but I'm really not sure. I've been researching about this for a while, but I never get a direct, straight forward/simple answer.

I don't understand why I get these, because I know the first time I kissed my boyfriend, I was fine. But currently, I get this weird, some what painful white circle thing on my bottom lip, touching my bottom teeth inside my mouth.

All I know, is that it goes away after about a week or so. I don't think my boyfriend gets these as well, because he never mentions it to me.

Could someone please explain why this happens? And please explain what I can do to make sure that whenever I kiss my boyfriend I don't get these canker/cold sore things.

Thank you very much!

Does he kiss too rough and it is causing you irritaion, perhaps.

I think a canker sore is inside the mouth and a cold sore is outside, wouldn't hurt to rinse your mouth out with salt water before you brush before bed, and maybe try wearing some kind of lip balm or gloss, this may help

hey.. yeah i have that same thing too! i kissed a boy last night and now my lip hurts really badly. I've never gotten this before and it sounds exactly how you're describing it. maybe it's from bumping up against each other too much and like "bruising" your lip? that's really the only thing i can think of. maybe it wouldn't happen if you switched it up when you're kissing (aka not always kiss on the "left side".. if that makes sense..). sorry!! i don't really know how to help- i just wanted to say something cause i have the exact same thing.