You, nor anyone one else, will have any respect for you if you lie. Period. I had a friend in high school who wanted me to tell her mom she was going to spend the night at my house, when she was really going to sneak and see a boy that her mom didn’t like. I told her to find another friend to do that for her because I refused. That was 17 years ago and she is still my friend to this day. The fact that I stood up for what was right did two things: 1, she respected me for it. 2, she ended up trusting me more than any other friend because I proved I was trustworthy. Yes, she wasn’t happy with me initially when I said no, but I knew if I lied and got caught, her mother wouldn’t let us be friends anymore. It’s not always easy to do what’s right. But, at the end of the day, it’s the best choice! Praying you make a wise decision…
The fact that you know that you’d feel guilty if you lied, means that you already know the answer to your question. Don’t lie to your friend’s mother.