He's slept with more than 15 girls

So hey ladies,
I just started dating this guy and he's really open about everything. He just recently told me that he's slept with more than 15 girls and has had a few threesomes. Knowing myself, there's no doubt that he's slept with a few people because he is a good looking guy but I didn't know it would be that many. 
I've been feeling a little uncomfortable about it. I know it's his past and it doesn't matter anymore, what matter is now and what we are. 
Should I tell him about what I'm feeling and be open about it? 
WHAT ARE YOUR THOUGHTS?
WHAT WOULD YOU HANDLE IT IF IT'S YOUR BF?
THANKS LADIES! 😘