My couple friends love to tease me because I'm a virgin

I'm a 24 year old guy, and all of my friends are in relationships. In fact, some of them are even engaged. I'm still a virgin. It's not like I've never had any chances to lose it, I've just been too chicken to go all the way. They love to tease me about it. They say things like "have you ever even seen a naked woman in person?" or "are you actually still a virgin?". I usually just smile and nod awkwardly and try to change the subject. I don't find it funny when they make jokes like that. I actually find it kind of hurtful. But I don't want to rock the boat.