Obligated to tell my Mom I’m having sex?!?!

Hey all, just wanted to share my story and hopefully I can receive as much advice as possible.

I’m currently a 20 year-old community college student who still lives with both parents (I’m planning to move out once I transfer next year school year)

About 6 months ago, I told my mother that I was going out with a guy. Yes, I had sex with him. Once I came home my mother had a suspicion that I had sex, so she came into my room and started to question me. I LOVE my mother to death, but I personally feel that topics like that are too personal to ask. At this age, I shouldn’t feel obligated to tell her that I did or did not have sex.

I ended up lying to her that I did not, because it’s almost as if she was making me feel ashamed if I did indeed have sex. Sex shouldn’t be a shameful thing.

I feel like this also has to do a lot with cultural upbringing, not to mention I come from a Mexican family where sensitive/personal topics can become too difficult to discuss within families. Atleast in my family.

What should I do?