What do you do when I a guy or a girl disqualifies you so that you remain alpha.

In the past few month, I've garnered a few examples of where girls and guys disqualify me. For instance, last weekend, I was hanging out with some friends at a cookout. I was sitting at the end of the table, and I was leading the conversation, and one girl there was being particular quiet, so I thought I would include her. I asked her how old she was, immediately one of the guys there says: "oh, she's too old for you." I just pretended I didn't hear that, and then I jokingly said, sweet, you can go buy us more booze when we run out then. She then told me a story about how she got in trouble with her parents after she and her boyfriend bought her sibling booze. It wasn't the story, but the subtext and the way she said was something to the extent of: even if I didn't have a boyfriend, I wouldn't go out with you. How do you respond to that and remain alpha?

Another time, I was hanging out with another guy (he's a dick) and a group of girls. The other guy was saying how he thought one of the girl's sister was really hot, and how he wanted to bang her really bad. The sister showed everyone there her sister's picture, and I asked if I could see it, so I said "hey, can I see it" and then I said, "Oh, she's really pretty". then the other guy said: "She's way out of your league man" and the sister said, "and she's too young for you too." It's not like I was even interested in her. I just ignored it because i didn't know how to respond.

FYI: I'm not bad looking, and I have a good fashion style