LW#1:
When a 5-year-old asks a question, all you have to do is answer tersely and honestly and they'll go back to their Legos. If they ask follow up questions, they're probably more worried about you and your spouse staying together than what happened with your mom. Just keep reiterating that they're in a loving family.
But seriously, your mom messed you up about your dad with her fraughtness. I can only imagine that, as a young woman in her 20s raising you, she was burdened both with some immaturity and society's disapprobation. Instead of worrying how you're going to talk to your kids, I think it's about time you sat down with mom and told her what's going on in your family, and that you don't want to make your kids feel shame and awfulness like you did.
The fact is, there may be reasons that she's so clammed-up about her ex. He ditched her when she was pregnant, for one thing. Who knows if they had "a relationship" or if there was some sort of acquaintance rape thing happening at your conception. Silence is usually a response to shame, and in my imagination, as I'm sure there is in yours, there is a whole range of scenarios that play themselves out. None of them are comfortable, and that may be one reason why although you know who your father is you have never met him.
Your task is to get one honest discussion out of your mother where you find out if all this silence and shame and general freaked-outedness can be dispersed. For you, not your mom. For your kids, with whom you want to walk in truth, even while protecting them from whatever it is that has put down such a cone of silence.
LW#2:
Find a situation where you can say: "Have you been following Battlestar Galactica? That Three De'Anna is such a duplicitous bitch, playing the Cylons off the Colonials. But she has to be, because there's only one of her left, and she can never be downloaded again into a duplicate body."
For the record: This is not my actual interpretation of Cylon model Three, De'Anna. I just think Battlestar Galactica needs to be referenced as far and wide as possible.
LW#3:
Your "friends" sound like underdeveloped gnatbrains. Drop them. Seriously. Maybe if you get up and walk away when they're concentrating on the flashy lights and "bing bing" noises they'll get not that they are being rude but that you deserve some attention, being right there in front of them and whatnot.
What is it with these constant texters? I don't get it. It eats up your SIM card or phone memory (depending on the phone, obvs), it isn't like you can text a conversation (though you can have one on the phone you're using) and to get an unlimited texting plan you get charged out the ying yang. I get it for wilderness rescue and for when you know the other person won't pick up the phone and you have discrete information to impart, but otherwise I don't see the appeal, especially when they're right there next to friends in the flesh. What makes the digital messages so appealing? There must be some Skinnerian thing going on.
Also, how do you actually type "H8" in text? I have a program that helps spell out the few texts I have sent in my time, and when I try to abbreviate and use "U" or whatever, like the kids do, to be ironic, it won't let me. Disabling this program only makes texting even more obnoxious. At the heart of it: Are texts today actually spelled out because of this clever predictive text or do "ppl" bother to turn it off or go through the "not this word" button-pressing so they can enter in "U want 2 get 2gether?"
LW#4:
So your friend is both liberated by and ashamed of the lowdown swinginess of her boobies? Yeah, something is going on.
The sports bra thing is a terrible idea made worse by the faux anonymity, the junior high clique-y ganging up-ness of it all. Whoever is closest to her should ask her if something is going on. God knows I feel self-conscious when my girls are unrestrained, and my sensitive bits are nowhere near chafing against my waistband. And when they get there in 20 years, God help me I will get them hitched up by modern medicine.
Funny thing. A couple of relatives of mine have had "medically necessary cosmetic surgery." Like no one could tell their baggy hooded eyes were bugging them; but without the "medically necessary" part they could not justify the surgery because it was all about vanity. God forbid they should just do something because they want to, especially something as minor as getting their eyelids lifted. I mean, own it, people. I'm owning my future boob lift. And maybe there is something happening that this woman feels too embarrassed to own under any banner except the one of "feminism" (note to first and second wavers: Bras are okay now, even sexy ones. No, they aren't empowering, but the ability to run and jump and escape from a collapsing building or mall shooter or whatever IS empowering).
If she's really owning her saggy, droopy "swing low sweet chariots," this should not be a tough conversation to breach. If she's not owning it, you need to be the supportive friends you should be (pun intended) to her.