Me being awkward

So, I want to talk about me close to girls. I have a ton of loyal friends and honestly, nobody from the boys has a problem with me and neither do I with them. Now, when it comes to girls.. In our class there are only 2 girls that are acting normal and you can talk to them. The problem is, that I always don’t know what to say when I’m around them. When we are close to them, my best friend almost everytime makes them laugh or just knows what to say. When I’m around them, I don’t really feel nervous, but the conversations are always so boring and dry. One of the 2 girls, actually wanted me like 3 years ago and I rejected her. The other one, wanted me now. I also rejected her ( I just don’t like the looks ).. But she is smart and understands. Now, there was a school event, where you would split into 4 boys and 2 girls. The 2 girls wanted two of my friends to be in the group ( one of them my best friend ) and then, they looked at me and my rly shy friend. ( I sit with the friend in class and I don’t really like him, he’s such a nerd, and just so quiet ) and i think that i got that from him. Well, when the girls looked at us, they said that they’re fine like this. So later during the day I asked one of the girls, why ? She said that me and my friend are too “serious”. This kinda broke me, I mean im sitting in class and yeah I don’t really like scream or do anything, im just on my phone with my best friend. And yeah now i just realized that so many people is comparing me to the shy and quiet friend im sitting with. So i just want to not be that like, serious and emotionless. Any tips ?