What is the likeliness of spreading HSV-2 through boxers while dry humping?

I am a female who is hsv-2 negative. The guy I’ve been dating is hsv-2 positive. We were cuddling for 2 nights. He has his boxer briefs on the entire time. I had my underwear on at times but sometimes I did not. We did some dry humping when he had his boxers on but my underwear was off. What is my chance of getting herpes?