Why do guys like protecting girls?

Whenever a guy would try to protect me or help me in some way, my heart almost always beats faster and I just melt. One time, my guy friend and I were walking in the street with another female friend, and he told me to get in front of him. I refused a few times because I told him that I was the oldest (a year older than him), and so I thought it was my responsibility to keep them safe, and then he said “Okay what if someone comes up to you with chloroform and I want be able to see/help you?” Again, my heart melted and I decided to listen to him for his own comfort lol.