To tell a lie is never a good thing, if you do not want to give an answer to a question say nothing.,change the subject. Ephesians 4:25 states, " Now that you have put away deceit, each one of you speak truth with his neighbor."
Tbh, I'm 18 years old and I recently got my first girlfriend. She was so happy when she found out that she was my first. Trust me when I say that most/some girls love being a guy's first in anything.