i saw your comment on another answer about how she came to stay over the weekend, and it could be two things 1) she feels a little rejected by her daughters love, that she came to stay with you for the weekend and you couldn't even wait 20 minutes while she stepped out and couldn't resist sex, may be she wanted quality mother daughter time, and seeing that you couldn't wait till she left, she probably feels like you didn't want her over and put your boyfriend over her
i don't know if my mom was over at my place, id tell my boyfriend and friends that id see them next week, id make my mom feel welcome and give her time for us ya know? or at least schedule a time that fits for both of us
or 2- she still sees you as her child and is in shock factor reality mode and doesn't know how to accept that you're an adult now, her baby is all grown up. may be she waited till marriage to have sex with your dad so to see you doing it before marriage may be she is disappointed.
its time you had the sex talk. every parent should have that with their kids.
Good Answer
She saw something she didn't want to see and doesn't know how to handle it. She's probably embarrassed more than anything - I'm sure you are too, and feeling that she's looking at you in a judgmental way is probably hyper-sensitivity to her reaction. You're both in stand-off anticipating each others' response.
I think the best anti-dote to this problem is an injection of humour. Just break the ice and say to her casually.. "hey ma, I'm sorry you had to see that other day.. pretty embarrassing, talk about timing!"
Once you get talking about it it'll soon be a thing of the past. If you show her you're willing to laugh at yourself, she knows she need not take it too seriously.
If it's any consolation I think it happens to everybody at some point.
Hope this helps. =)
Imagine walking in on your parents having sex...EXACTLY.You would be mortified and probably want to temporarily spoon your eyeballs out of their sockets.She is your mom,and always will be.Some parents see their children as adolscents for the rest of their life.Your mom probably didn't even think you knew what sex was,or that she would even see you DOING it for that matter.She will be ready to talk about it once she has come to terms with the fact that you an adult.In the interim,give her some time to process it.Put yourself in her shoes for a bit.When some time has gone by,then approach her about it.
Its an awkward situtation to step into, she'll forget in due time, this is like you walking in on your mom an dad having sex, kinda a weird feeling lol.
Scroll Down to Read Other Opinions
What's Your Opinion? Sign Up Now!Is she one of those parents that drill *No sex before marriage? if so, its self explantory.
Number one you need a better lock.
Number two your old enough to have sex tell this to your mom because
It's your apparent and you pay bills
Her image of you is tarnished but after time passes she will get over it. Do nothing
How did she walk in on you guys in YOUR apartment?
She was staying with me for the weekend so she had her own key. She went out so we thought we were safe and she returned a littler earlier than expected :(
lol oh... Well that's your personal business I don't know why she's so upset about it.
She's not mad. It's an awkward situation no one wants to be in
She'll get over it
She needs time
Sexual Relationships 
Sexual Health 
Most Helpful Girls