Is it normal that my mom won't let me spend the night w/ my boyfriend?

My best guess she see's you staying over there as announcing to the world that the two of you are sleeping together.
If you two just fuck someplace and leave, people might just think you two were just hanging out but if you stay the night, anyone who see's you two leave would automatically assume you are having sex.

Now if that sounds crazy, I agree it kind of is but look at it from your mom's point of view. I don't know your mother but from the way you've put things I'm assuming she doesn't like the idea of you two having sex but she understands you're going to do it. What is probably upsetting her so much is that she is afraid If you stay over it will become undeniable to anyone that you are sexually active and she's afraid of that information getting out and people thinking that you are a slut and if they think you are slut they will disrespect you.

Your mom knows you better than we do. Besides, you don't sound too bright.

If you don't like her rules then move out. You don't understand her logic, she and your dad have been together over 20 years so not comparable to you and your bf. Get over yourself

Ask your Mom to join in for a threesome.
Have you or your Mom ever seen his cock and nuts ?

She's probably just a man-hating prick from her choice of words. I suggest you should not let her control your life.

She probably doesn't want you treating her home like a hotel while flouting her rules. It's disrespectful. Yes, you are legally an adult, but you're still living in her home. Respect her rules while living there, and if you want to do something outside of the boundaries she has set, then focus your energies on getting your own place where you get to make the rules.

You're mom should let you spend the night
with your boyfriend, heck my mom would call
this girl off from school and this girl would
spend the whole day with me, i really loved the
girl but nothing sexual went on cause of our age
but your mom needs to face things, if she's worried
that your having sex than she needs to get you on
birth control such as implant, shot would be best
i mean there is nothing no can do we all have
experimented with sexual activity and such.

At your age you are free to move out of the house and go live on your own and do whatever you want. I don't know if religion is involved, if so i think you already have the answer to why your mother thinks that way.

Maybe she wants him

She sounds like she is old fashion.

You should show her the used rubber johnnies.

she fears he's going to insert his long john inside you

This is just my opinion, but it sounds like she's reliving her youth through you, and being overprotective and controlling so you don't make the same mistakes she may have made at your age; or she's treating you like how her mother treated her, or a combination of both.

Whatever the reason may be, it's clear she doesn't see you as a responsible young adult, and the best thing you can do is work toward moving out.